Laser beam generation system employing a laser diode and high-frequency modulation circuitry mounted on a flexible circuit

ABSTRACT

A laser beam generation system having an integrated coherence reduction mechanism. The system includes: a flexible circuit having a first end portion and a second end portion; a laser diode mounted on the first end portion of the flexible circuit, for producing a laser beam having a central characteristic wavelength; diode current drive circuitry for producing a diode drive current to drive the laser diode and produce said laser beam; and high frequency modulation (HFM) circuitry also mounted on the first end portion of the flexible circuit, for modulating the diode drive current at a sufficiently high frequency to cause the laser diode to produce a laser beam having a spectral side-band components about the central characteristic wavelength, and thereby reducing the coherence as well as coherence length of the laser beam.

CROSS-REFERENCE TO RELATED U.S. APPLICATIONS

This is a Continuation of copending application Ser. No. 11/880,087filed Jul. 19, 2007, which is a Continuation-in-Part (CIP) of thefollowing applications: U.S. application Ser. No. 11/820,497 filed Jun.19, 2007; U.S. application Ser. No. 11/820,010 filed Jun. 15, 2007; U.S.application Ser. No. 11/809,173 filed May 31, 2007; U.S. applicationSer. No. 11/809,174 filed May 31, 2007; U.S. application Ser. No.11/809,240 filed May 31, 2007; U.S. application Ser. Nos. 11/809,238filed May 31, 2007; 11/788,769 filed Apr. 20, 2007; InternationalApplication No. PCT/U.S.07/09763 filed Apr. 20, 2007; U.S. applicationSer. No. 11/731,866 filed Mar. 30, 2007; U.S. application Ser. No.11/731,905 filed Mar. 30, 2007; U.S. application Ser. No. 11/729,959filed Mar. 29, 2007; U.S. application Ser. No. 11/729,525 filed Mar. 29,2007; U.S. application Ser. No. 11/729,945 filed Mar. 29, 2007; U.S.application Ser. No. 11/729,659 filed Mar. 29, 2007; U.S. applicationSer. No. 11/729,954 filed Mar. 29, 2007; U.S. application Ser. No.11/810,437 filed Mar. 29, 2007; U.S. application Ser. No. 11/713,535filed Mar. 2, 2007; U.S. application Ser. No. 11/811,652 filed Mar. 2,2007; U.S. application Ser. No. 11/713,785 filed Mar. 2, 2007; U.S.application Ser. No. 11/712,588 filed Feb. 28, 2007; U.S. applicationSer. No. 11/712,605 filed Feb. 28, 2007; U.S. application Ser. No.11/711,869 filed Feb. 27, 2007; U.S. application Ser. No. 11/711,870filed Feb. 27, 2007; U.S. application Ser. No. 11/711,859 filed Feb. 27,2007; U.S. application Ser. No. 11/711,857 filed Feb. 27, 2007; U.S.application Ser. No. 11/711,906 filed Feb. 27, 2007; U.S. applicationSer. No. 11/711,907 filed Feb. 27, 2007; U.S. application Ser. No.11/711,858 filed Feb. 27, 2007; U.S. application Ser. No. 11/711,871filed Feb. 27, 2007; U.S. application Ser. No. 11/640,814 filed Dec. 18,2006; International Application No. PCT/US06/48148 filed Dec. 18, 2006;U.S. application Ser. No. 11/489,259 filed Jul. 19, 2006; U.S.application Ser. No. 11/408,268 filed Apr. 20, 2006; U.S. applicationSer. No. 11/305,895 filed Dec. 16, 2005; U.S. application Ser. No.10/989,220 filed Nov. 15, 2004; U.S. application Ser. No. 10/712,787filed Nov. 13, 2003, now U.S. Pat. No. 7,128,266; U.S. application Ser.No. 10/186,320 filed Jun. 27, 2002, now U.S. Pat. No. 7,164,810; Ser.No. 10/186,268 filed Jun. 27, 2002, now U.S. Pat. No. 7,077,319;International Application No. PCT/US2004/0389389 filed Nov. 15, 2004,and published as WIPO Publication No. WO 2005/050390; U.S. applicationSer. No. 09/990,585 filed Nov. 21, 2001, now U.S. Pat. No. 7,028,899 B2;U.S. application Ser. No. 09/781,665 filed Feb. 12, 2001, now U.S. Pat.No. 6,742,707; U.S. application Ser. No. 09/780,027 filed Feb. 9, 2001,now U.S. Pat. No. 6,629,641 B2; and U.S. application Ser. No. 09/721,885filed Nov. 24, 2000, now U.S. Pat. No. 6,631,842 B1; wherein each saidapplication is commonly owned by Assignee, Metrologic Instruments, Inc.,of Blackwood, N.J., and is incorporated herein by reference as if fullyset forth herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates generally to digital image capturing andprocessing scanners of ultra-compact design capable of reading bar codesymbols in point-of-sale (POS) and other demanding scanningenvironments.

2. Brief Description of the State of Knowledge in the Art

The use of bar code symbols for product and article identification iswell known in the art. Presently, various types of bar code symbolscanners have been developed for reading bar code symbols at retailpoints of sale (POS). In general, these bar code symbol readers can beclassified into two (2) distinct classes.

The first class of bar code symbol reader uses a focused light beam,typically a focused laser beam, to sequentially scan the bars and spacesof a bar code symbol to be read. This type of bar code symbol scanner iscommonly called a “flying spot” scanner as the focused laser beamappears as “a spot of light that flies” across the bar code symbol beingread. In general, laser bar code symbol scanners are sub-classifiedfurther by the type of mechanism used to focus and scan the laser beamacross bar code symbols.

The second class of bar code symbol readers simultaneously illuminateall of the bars and spaces of a bar code symbol with light of a specificwavelength(s) in order to capture an image thereof for recognition anddecoding purposes.

The majority of laser scanners in the first class employ lenses andmoving (i.e. rotating or oscillating) mirrors and/or other opticalelements in order to focus and scan laser beams across bar code symbolsduring code symbol reading operations. Examples of hand-held laserscanning bar code readers are described in U.S. Pat. Nos. 7,007,849 and7,028,904, incorporated herein by reference in its entirety. Examples ofLaser scanning presentation bar code readers are described in U.S. Pat.No. 5,557,093, incorporated herein by reference in its entirety. Otherexamples of bar code symbol readers using multiple laser scanningmechanisms are described in U.S. Pat. No. 5,019,714, incorporated hereinby reference in its entirety.

In demanding retail environments, such as supermarkets and high-volumedepartment stores, where high check-out throughput is critical toachieving store profitability and customer satisfaction, it is commonfor laser scanning bar code reading systems to have both bottom andside-scanning windows to enable highly aggressive scanner performance.In such systems, the cashier need only drag a bar coded product pastthese scanning windows for the bar code thereon to be automatically readwith minimal assistance of the cashier or checkout personal. Such dualscanning window systems are typically referred to as “bioptical” laserscanning systems as such systems employ two sets of optics disposedbehind the bottom and side-scanning windows thereof. Examples ofpolygon-based bioptical laser scanning systems are disclosed in U.S.Pat. Nos. 4,229,588; 4,652,732 and 6,814,292; each incorporated hereinby reference in its entirety.

Commercial examples of bioptical laser scanners include: the PSC8500-6-sided laser based scanning by PSC Inc.; PSC 8100/8200, 5-sidedlaser based scanning by PSC Inc.; the NCR 7876-6-sided laser basedscanning by NCR; the NCR7872, 5-sided laser based scanning by NCR; andthe MS232x Stratos®H, and MS2122 Stratos® E Stratos 6 sided laser basedscanning systems by Metrologic Instruments, Inc., and the MS2200Stratos®S 5-sided laser based scanning system by Metrologic Instruments,Inc.

In general, prior art bioptical laser scanning systems are generallymore aggressive that conventional single scanning window systems.However, while prior art bioptical scanning systems represent atechnological advance over most single scanning window system, prior artbioptical scanning systems in general suffer from various shortcomingsand drawbacks. In particular, the scanning coverage and performance ofprior art bioptical laser scanning systems are not optimized. Thesesystem are generally expensive to manufacture by virtue of the largenumber of optical components presently required to construct such laserscanning systems. Also, they require heavy and expensive motors whichconsume significant amounts of electrical power and generate significantamounts of heat.

In the second class of bar code symbol readers, early forms of linearimaging scanners were commonly known as CCD scanners because they usedCCD image detectors to detect images of the bar code symbols being read.Examples of such scanners are disclosed in U.S. Pat. Nos. 4,282,425, and4,570,057.

In more recent times, hand-held imaging-based bar code readers employingarea-type image sensing arrays based on CCD and CMOS sensor technologieshave gained increasing popularity.

In Applicants' WIPO Publication No. WO 2005/050390, entitled“HAND-SUPPORTABLE IMAGING-BASED BAR CODE SYMBOL READER SUPPORTINGNARROW-AREA AND WIDE-AREA MODES OF ILLUMINATION AND IMAGE CAPTURE”,incorporated herein by reference, a detailed history of hand-handimaging—based bar code symbol readers is provided, explaining that manyproblems that had to be overcome to make imaging-based scannerscompetitive against laser-scanning based bar code readers. MetrologicInstruments' Focus® Hand-Held Imager is representative of an advance inthe art which has overcome such historical problems. An advantage of 2Dimaging-based bar code symbol readers is that they are omni-directionalby nature of image capturing and processing based decode processingsoftware that is commercially available from various vendors.

U.S. Pat. No. 6,766,954 to Barkan et al proposes a combination of linearimage sensing arrays in a hand-held unit to form an omni-directionalimaging-based bar code symbol reader. However, this hand-held imager haslimited application to 1D bar code symbols, and is extremely challengedin reading 2D bar code symbologies at POS applications.

WIPO Publication No. WO 2005/050390 (assigned to Metrologic InstrumentsInc.) discloses POS-based digital imaging systems that are triggered toilluminate objects with fields of visible illumination from LED arraysupon the automatic detection of objects within the field of view of suchsystems using IR-based object detection techniques, and then capture andprocess digital images thereof so as to read bar code symbolsgraphically represented in the captured images.

US Patent Publication No. 2006/0180670 to PSC Scanning, Inc. alsodiscloses digital imaging systems for use at the point of sale (POS),which are triggered to illuminate objects with visible illumination uponthe detection thereof using IR-based object detection techniques.

U.S. Pat. No. 7,036,735 to Hepworth et al disclose an imaging-based barcode reader, in which both visible (i.e. red) and invisible (i.e. IR)light emitting diodes (LEDs) are driven at different illuminationintensity levels during object illumination and image capture operationsso as to achieve a desired brightness in captured images, while seekingto avoid discomfort to the user of the bar code reader.

Also, US Patent Publication No. 2006/0113386 to PSC Scanning, Inc.discloses methods of illuminating bar coded objects using pulses ofLED-based illumination at a rate in excess of the human flicker fusionfrequency, synchronized with the exposures of a digital imager, and evenat different wavelengths during sequential frame exposures of theimager. Similarly, the purpose with this approach is to be able to readbar code symbols printed on substrates having different kinds of surfacereflectivity characteristics, with the added benefit of being lessvisible to the human eye.

However, despite the increasing popularity in area-type hand-held andpresentation type imaging-based bar code symbol reading systems, andeven with such proposed techniques for improved LED-based illuminationof objects at POS and like imaging environments, such prior art systemsstill cannot complete with the performance characteristics ofconventional laser scanning bi-optical bar code symbol readers at POSenvironments. Also, the very nature of digital imaging presents otherproblems which makes the use of this technique very challenging in manyapplications.

For example, in high-speed imaging acquisition applications, as would bethe case at a retail supermarket, a short exposure time would be desiredto avoid motion blurring at the POS station. One know way of reducingthe exposure time of the digital image detection array is by increasingthe intensity level of the illumination beam used to illuminate theobject during illumination and imaging operations. However, at POSenvironments, the use of high intensity laser illumination levels is notpreferred from the point of view of customers, and cashiers alike,because high brightness levels typically cause discomfort and fatiguedue to the nature of the human vision system and human perceptionprocesses.

And while it is known that IR illumination can be used to form anddetect digital images of bar coded labels, the use of infraredillumination degrades the image contrast quality when bar codes areprinted on the thermal printing paper. Consequently, low contrast imagessignificantly slows down imaging-based barcode decoding operations,making such operations very challenging, if not impossible at times.

In WIPO Publication No. WO 2002/043195, entitled “PLANAR LASERILLUMINATION AND IMAGING (PLIIM) SYSTEMS WITH INTEGRATED DESPECKLINGMECHANISMS PROVIDED THEREIN”, incorporated herein by reference,Applicants address the issues of using laser illumination in digitalimaging barcode reading systems, namely, the inherent problem of opticalnoise generated by laser speckles in detected digital images. Suchspeckle pattern noise, as its often called, is caused by randominterferences generated by a rough paper surface, ultimately producingsignal variations on the order of size of the bars and spaces of thebarcode, resulting in inaccurate imaging and poor decoding. Reduction ofthis noise is highly desirable.

While WIPO Publication No. WO/2002/043195 discloses and teaches many newways to despeckle a laser illumination beam, there is still a great needfor improved techniques for implementing such laser beam despecklingtechniques which are reliable in operation, easy and inexpensive to massproduce.

Thus, there is a great need in the art for improved digital imagecapture and processing systems that are capable of competing withconventional laser scanning bar code readers employed in demanding POSenvironments, and providing the many advantages offered by imaging-basedbar code symbol readers, while avoiding the shortcomings and drawbacksof such prior art systems and methodologies.

OBJECTS AND SUMMARY OF THE PRESENT INVENTION

Accordingly, a primary object of the present invention is to provideimproved digital image capturing and processing apparatus for use in POSenvironments, which are free of the shortcomings and drawbacks of priorart laser scanning and digital imaging systems and methodologies.

Another object of the present invention is to provide such a digitalimage capturing and processing apparatus in the form of anomni-directional digital image capturing and processing based bar codesymbol reading system that employs advanced coplanar illumination andimaging technologies.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system, comprising a plurality of coplanar illumination andimaging stations (i.e. subsystems), generating a plurality of coplanarlight illumination beams and field of views (FOVs), that are projectedthrough and intersect above an imaging window to generate a complex oflinear-imaging planes within a 3D imaging volume for omni-directionalimaging of objects passed therethrough.

Another object of the present invention is to provide suchomni-directional image capturing and processing based bar code symbolreading system, wherein the plurality of coplanar light illuminationbeams can be generating by an array of coherent or incoherent lightsources.

Another object of the present invention is to provide suchomni-directional image capturing and processing based bar code symbolreading system, wherein the array of coherent light sources comprises anarray of visible laser diodes (VLDs).

Another object of the present invention is to provide suchomni-directional image capturing and processing based bar code symbolreading system, wherein the array of incoherent light sources comprisesan array of light emitting diodes (LEDs).

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system, wherein is capable of reading (i) bar code symbolshaving bar code elements (i.e., ladder type bar code symbols) that areoriented substantially horizontal with respect to the imaging window, aswell as (ii) bar code symbols having bar code elements (i.e.,picket-fence type bar code symbols) that are oriented substantiallyvertical with respect to the imaging window.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system, which comprises a plurality of coplanar illumination andimaging stations (i.e. subsystems), each of which produces a coplanarPLIB/FOV within predetermined regions of space contained within a 3-Dimaging volume defined above the imaging window of the system.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system, wherein each coplanar illumination and imaging stationcomprises a planar light illumination module (PLIM) that generates aplanar light illumination beam (PLIB) and a linear image sensing arrayand field of view (FOV) forming optics for generating a planar FOV whichis coplanar with its respective PLIB.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system, comprising a plurality of coplanar illumination andimaging stations, each employing a linear array of laser light emittingdevices configured together, with a linear imaging array withsubstantially planar FOV forming optics, producing a substantiallyplanar beam of laser illumination which extends in substantially thesame plane as the field of view of the linear array of the station,within the working distance of the 3D imaging volume.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system, having an electronic weigh scale integrated with thesystem housing.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system, comprising a plurality of coplanar illumination andimaging stations strategically arranged within an ultra-compact housing,so as to project out through an imaging window a plurality of coplanarillumination and imaging planes that capture omni-directional views ofobjects passing through a 3D imaging volume supported above the imagingwindow.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system comprising a plurality of coplanar illumination andimaging stations, each employing an array of planar laser illuminationmodules (PLIMs).

Another object of the present invention is to provide such anomni-directional image capturing and processing based bar code symbolreading system, wherein at each coplanar illumination and imagingstation, an array of VLDs concentrate their output power into a thinillumination plane which spatially coincides exactly with the field ofview of the imaging optics of the coplanar illumination and imagingstation, so very little light energy is wasted.

Another object of the present invention is to provide such anomni-directional image capturing and processing based bar code symbolreading system, wherein each planar illumination beam is focused so thatthe minimum width thereof occurs at a point or plane which is thefarthest object distance at which the system is designed to captureimages within the 3D imaging volume of the system.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system, wherein at each coplanar illumination and imagingstation, an object need only be illuminated along a single plane whichis coplanar with a planar section of the field of view of the imageformation and detection module being used in the system.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system, wherein low-power, light-weight, high-response,ultra-compact, high-efficiency solid-state illumination producingdevices, such as visible laser diodes (VLDs), are used to selectivelyilluminate ultra-narrow sections of a target object during imageformation and detection operations.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system, wherein the planar laser illumination technique enablesmodulation of the spatial and/or temporal intensity of the transmittedplanar laser illumination beam, and use of simple (i.e. substantiallymonochromatic) lens designs for substantially monochromatic opticalillumination and image formation and detection operations.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system employing a plurality of coplanar illumination andimaging stations, wherein each such station includes a linear imagingmodule realized as an array of electronic image detection cells (e.g.CCD) having programmable integration time settings, responsive to theautomatically detected velocity of an object being imaged, for enablinghigh-speed image capture operations.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system employing a plurality of coplanar illumination andimaging stations, wherein at each such station, a pair of planar laserillumination arrays are mounted about an image formation and detectionmodule having a field of view, so as to produce a substantially planarlaser illumination beam which is coplanar with the field of view duringobject illumination and imaging operations, and one or more beam/FOVfolding mirrors are used to direct the resulting coplanar illuminationand imaging plane through the imaging window of the system.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system employing a plurality of coplanar illumination andimaging stations, wherein each such station supports an independentimage generation and processing channel that receives frames of linear(1D) images from the linear image sensing array and automaticallybuffers these linear images in video memory and automatically assemblesthese linear images to construct 2D images of the object taken along thefield of view of the coplanar illumination and imaging plane associatedwith the station, and then processes these images using exposure qualityanalysis algorithms, bar code decoding algorithms, and the like.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system capable of reading PDF bar codes for age verification,credit card application and other productivity gains.

Another object of the present invention is to provide a omni-directionalimage capturing and processing based bar code symbol reading systemcapable of reading PDF and 2D bar codes on produce—eliminating keyboardentry and enjoying productivity gains.

Another object of the present invention is to provide such anomni-directional image capturing and processing based bar code symbolreading system which supports intelligent image-based object recognitionprocesses that can be used to automate the recognition of objects suchas produce and fruit in supermarket environments.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system having an integrated electronic weight scale, an RFIDmodule, and modular support of wireless technology (e.g. BlueTooth andIEEE 802.11(g)).

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system capable of reading bar code symbologies independent ofbar code orientation.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system having a 5 mil read capability.

Another object of the present invention is to provide a omni-directionalimage capturing and processing based bar code symbol reading systemhaving a below counter depth not to exceed 3.5″ (89 mm).

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system having direct connect power for PlusPower USB Ports.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system having an integrated scale with its load cell positionedsubstantially in the center of weighing platform.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system having an integrated Sensormatic® deactivation device,and an integrated Checkpoint® EAS antenna.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system employing cashier training software, and productivitymeasurement software showing how an operator actually oriented packagesas they were scanned by the system.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system having flash ROM capability.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system that can power a hand held scanner.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system having a mechanism for weighing oversized produce.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system having excellent debris deflecting capabilities.

Another object of the present invention is to provide anomni-directional image capturing and processing based bar code symbolreading system that is capable of reading all types of poor qualitycodes—eliminating keyboard entry and enjoying productivity gains.

Another object of the present invention is to provide an image capturingand processing scanner based high throughput scanner that can addressthe needs of the supermarket/hypermarket and grocery store marketsegment.

Another object of the present invention is to provide an image capturingand processing scanner having a performance advantage that leads toquicker customer checkout times and productivity gain that cannot bematched by the conventional bioptic laser scanners.

Another object of the present invention is to provide a high throughputimage capturing and processing scanner which can assist in loweringoperational costs by exceptional First Pass Read Rate scanning and oneproduct pass performance, enabling sales transactions to be executedwith no manual keyboard entry required by the operator.

Another object of the present invention is to provide a high performanceimage capturing and processing checkout scanner that can meet theemerging needs of retailers to scan PDF and 2D bar codes for ageverification and produce items.

Another object of the present invention is to provide high performanceimage capturing and processing scanner capable of capturing the imagesof produce and products for price lookup applications.

Another object of the present invention is to provide a digital imagecapturing and processing scanner that provides a measurable advancementin First Pass Read Rate scanning with the end result leading tonoticeable gains in worker productivity and checkout speed.

Another object of the present invention is to provide a digital imagecapturing and processing scanner that employs no moving partstechnology, has a light weight design and offers a low cost solutionthat translate easily into a lower cost of ownership.

Another object of the present invention is to provide such digital imagecapturing and processing based bar code symbol reading system, whereinautomatic object motion detection and analysis is used to intelligentlycontrol the illumination fields during object illumination and imagingoperations to as to minimize the amount of visible illumination that isrequired to capture and detect high contrast and quality images fordiverse image processing applications (e.g. bar code reading, OCR,intelligent object recognition, etc) at retail POS environments.

Another object of the present invention is to provide such digital imagecapturing and processing based bar code symbol reading system, whereinboth visible and invisible forms of illumination are dynamicallyproduced from arrays of visible and invisible LEDs that are dynamicallycontrolled in response to real-time image contrast analysis of captureddigital images.

Another object of the present invention is to provide a POS-baseddigital image capturing and processing system employing a plurality ofarea-type digital image detecting arrays and methods of intelligentlyilluminating objects with the 3D imaging volume thereof, using automaticobject motion detection techniques and spectral-mixing illuminationtechniques to minimize the amount of visible illumination energy/powerrequired to capture sufficiently high-contrast images and successfullyprocess (i.e. decode process) the same.

Another object of the present invention is to provide novel methods ofnarrow area and/or wide-area illumination using dynamically/adaptivelycontrolled mixing of spectral illumination energy (e.g. visible and IRillumination) to form and detect digital images of objects at POSenvironments with sufficiently high image contrast and quality.

Another object of the present invention is to provide such methods ofnarrow area and/or wide-area illumination using VLDs and IR laser diodes(LDs).

Another object of the present invention is to provide such methods ofnarrow area and/or wide-area illumination using visible and IR LEDs.

Another object of the present invention is to provide such methods ofnarrow area and wide-area illumination using statically set ratios ofvisible and IR illumination energy/power.

Another object of the present invention is to provide such methods ofnarrow area and wide-area illumination using dynamically programmedratios of visible and IR illumination energy/power.

Another object of the present invention is to provide a method ofdriving a plurality of visible and invisible laser diodes so as toproduce an illumination beam having a dynamically managed ratio ofvisible to invisible (IR) spectral energy/power during objectillumination and imaging operations.

Another object of the present invention is to provide such a diodedriving method comprising: (A) supplying a plurality of visible laserand invisible laser diodes with a predetermined/default values of diodedrive currents to illuminate the object with a spectral mixture ofillumination during object illumination and imaging operations; (B)capturing one or more digital images of the illuminated object andmeasuring (in real-time) image contrast quality so as to generatefeedback or control data; and (C) using this feedback or control data todynamically generate the necessary values for the adjusted diode drivecurrents that are used to drive said visible and invisible laser diodesand an illumination beam having a dynamically managed ratio of visibleto invisible (IR) spectral energy/power required to produce images ofsufficient image contrast to ensure satisfactory image processing, whileminimizing visual brightness (to humans) at a POS station during objectillumination and imaging operations.

Another object of the present invention is to provide such a method,wherein the illumination beam is an illumination beam selected from thegroup consisting of planar, narrow-area and wide-area illuminationbeams.

Another object of the present invention is to provide a method ofdriving a plurality of visible and invisible LEDs so as to produce anillumination beam having a dynamically managed ratio of visible toinvisible (IR) spectral energy/power during object illumination andimaging operations.

Another object of the present invention is to provide such a LED drivingmethod comprising the steps of: (A) supplying a plurality of visible andinvisible LEDs with a predetermined/default values of diode drivecurrents to illuminate the object with a spectral mixture ofillumination during object illumination and imaging operations; (B)capturing one or more digital images of the illuminated object andmeasuring (in real-time) image contrast quality so as to generatefeedback or control data; and (C) using this feedback or control data todynamically generate the necessary values for the adjusted diode drivecurrents that are used to drive said visible and invisible LEDs and anillumination beam having a dynamically managed ratio of visible toinvisible (IR) spectral energy/power required to produce images ofsufficient image contrast to ensure satisfactory image processing, whileminimizing visual brightness (to humans) at a POS station during objectillumination and imaging operations.

Another object of the present invention is to provide such a method,wherein the illumination beam is an illumination beam selected from thegroup consisting of planar, narrow-area and wide-area illuminationbeams.

Another object of the present invention is to provide a coplanar laserillumination and imaging subsystem (i.e. station) deployable in anomni-directional image capturing and processing system, and comprising(i) an image formation and detection (IFD) subsystem having an imagesensing array and optics providing a field of view (FOV) on the imagesensing array, (ii) an spectral-mixing based illumination subsystemproducing a first field of visible illumination (produced from an arrayof VLDs) and a second field of invisible illumination (produced from anarray of IR LDs) that spatially overlap and spatially/temporallyintermix with each other while having a preset relative power ratio(VIS/IR), and are substantially coplanar or coextensive with the FOV ofthe image sensing array, (iii) an integrated laser despeckling mechanismassociated the IFD subsystem, (iv) an image capturing and bufferingsubsystem for capturing and buffering images from the image sensingarray, (v) an automatic object motion/velocity detection subsystem forautomatically detecting the motion and velocity of an object movingthrough at least a portion of the FOV of the image sensing array, and(vi) a local control subsystem for controlling the operations of thesubsystems within the illumination and imaging station.

Another object of the present invention is to provide a coplanar laserillumination and imaging subsystem (i.e. station) deployable in anomni-directional image capturing and processing system and comprising(i) an image formation and detection (IFD) subsystem having an imagesensing array and optics providing a field of view (FOV) on the imagesensing array, (ii) an spectral-mixing based illumination subsystemproducing a first field of visible illumination (produced from an arrayof VLDs) and a second field of invisible illumination (produced from anarray of IRLDs) that spatially overlap and spatially/temporally intermixwith each other while having a preset relative power ratio (VIS/IR), andare substantially coplanar or coextensive with the FOV of the imagesensing array, (iii) an integrated laser despeckling mechanismassociated the IFD subsystem (using the high-frequency modulation HFMtechniques, and optical multiplexing (OMUX) techniques, (iv) an imagecapturing and buffering subsystem for capturing and buffering imagesfrom the image sensing array, (v) an automatic object motion/velocitydetection subsystem for automatically detecting the motion and velocityof an object moving through at least a portion of the FOV of the imagesensing array, and (vi) a local control subsystem for controlling theoperations of the subsystems within the illumination and imagingstation.

Another object of the present invention is to provide a coplanar laserillumination and imaging subsystem (i.e. station) deployable in anomni-directional image capturing and processing system, and comprising(i) an image formation and detection (IFD) subsystem having an imagesensing array and optics providing a field of view (FOV) on the imagesensing array, (ii) an spectral-mixing based illumination subsystemproducing a first field of visible illumination (produced from an arrayof VLDs) and a second field of invisible illumination (produced from anarray of IRLDs) that spatially overlap and spatially/temporally intermixwith each other while having an adaptively/dynamically set relativepower ratio (VIS/IR), and are substantially coplanar or coextensive withthe FOV of the image sensing array, (iii) an integrated laserde-speckling mechanism associated the IFD subsystem as disclosed in WIPOPublication No. WO/2002/043195 or in the present Specification, (iv) animage capturing and buffering subsystem for capturing and bufferingimages from the image sensing array, (v) an automatic objectmotion/velocity detection subsystem for automatically detecting themotion and velocity of an object moving through at least a portion ofthe FOV of the image sensing array, and (vi) a local control subsystemfor controlling the operations of the subsystems within the illuminationand imaging station.

Another object of the present invention is to provide a method ofadaptively/dynamically controlling the spectral composition of theplanar illumination beam produced from the illumination subsystem of thecoplanar laser illumination and imaging subsystem (i.e. station).

Another object of the present invention is to provide a coplanar laserillumination and imaging subsystem (i.e. station) deployable in anomni-directional image capturing and processing system, and comprising(i) an image formation and detection (IFD) subsystem having an imagesensing array and optics providing a field of view (FOV) on the imagesensing array, (ii) an spectral-mixing based illumination subsystemproducing a first field of visible illumination (produced from an arrayof VLDs) and a second field of invisible illumination (produced from anarray of IRLDs) that spatially overlap and spatially/temporally intermixwith each other while having a adaptively/dynamically set relative powerratio (VIS/IR), and are substantially coplanar or coextensive with theFOV of the image sensing array, (iii) an integrated laser de-specklingmechanism associated the IFD subsystem (using the high-frequencymodulation HFM techniques, and optical multiplexing (OMUX) techniques ofthe present invention, (iv) an image capturing and buffering subsystemfor capturing and buffering images from the image sensing array, (v) anautomatic object motion/velocity detection subsystem for automaticallydetecting the motion and velocity of an object moving through at least aportion of the FOV of the image sensing array, and (vi) a local controlsubsystem for controlling the operations of the subsystems within theillumination and imaging station.

Another object of the present invention is to provide a flow chartillustrating the steps involved in the method of adaptively/dynamicallycontrolling the spectral composition of the planar illumination beamproduced from the illumination subsystem of the coplanar laserillumination and imaging subsystem (i.e. station).

Another object of the present invention is to provide a coplanarillumination and imaging subsystem (i.e. station) deployable in anomni-directional image capturing and processing system, and comprising(i) an image formation and detection (IFD) subsystem having an imagesensing array and optics providing a field of view (FOV) on the imagesensing array, (ii) an spectral-mixing based illumination subsystemproducing a first field of incoherent visible illumination (producedfrom an array of visible LEDs) and a second field of incoherentinvisible illumination (produced from an array of IR LEDs) thatspatially overlap and spatially/temporally intermix with each otherwhile having a adaptively/dynamically set relative power ratio (VIS/IR),and are substantially coplanar or coextensive with the FOV of the imagesensing array, (iii) an image capturing and buffering subsystem forcapturing and buffering images from the image sensing array, (iv) anautomatic object motion/velocity detection subsystem for automaticallydetecting the motion and velocity of an object moving through at least aportion of the FOV of the image sensing array, and (v) a local controlsubsystem for controlling the operations of the subsystems within theillumination and imaging station.

Another object of the present invention is to provide a method ofadaptively/dynamically controlling the spectral composition of a planarillumination beam produced from an illumination subsystem deployed in acoplanar illumination and imaging system.

Another object of the present invention is to provide a planar laserillumination array (PLIA) system capable of producing adynamically/adaptively managed mixture of invisible and visibleillumination energy generated by a linear array ofdynamically/adaptively driven VLD-based planar laser illuminationmodules (PLIMs) and IRLD-based PLIMs, each being operated under thecontrol of a local control subsystem, in response to control dataproduced by an image processing subsystem running a spectral-mixturecontrol algorithm.

Another object of the present invention is to provide A laser beamdespeckling device comprising: a laser diode for producing a laser beamhaving a central characteristic wavelength; diode current drivecircuitry for producing a diode drive current to drive the laser diodeand produce the laser beam; high frequency modulation (HFM) circuitryfor modulating the diode drive current at a sufficiently high frequencyto cause the laser diode to produce the laser beam having a spectralside-band components about the central characteristic wavelength, andreducing the coherence as well as coherence length of the laser beam;and an optical beam multiplexing (OMUX) module for receiving the laserbeam as an input beam, a generating as output, a plurality of laser beamcomponents that are recombined to produce a composite laser beam havingsubstantially reduced coherence for use in illumination applicationswhere a substantial reduction in speckle pattern noise is achieved.

Another object of the present invention is to provide such a laser beamdespeckling device, wherein illumination applications include digitalimaging, projection television, photolithographic illuminationoperations, etc).

Another object of the present invention is to provide such alaser-despeckling device, wherein the laser diode can be a visible laserdiode (VLD) or an invisible laser diode such as an IR laser diode(IRLD).

Another object of the present invention is to provide alaser-despeckling PLIM comprising a cylindrical illumination lens array,an OMUX module, a VLD, a high frequency modulation (HFM) circuitry and adiode current drive circuitry, wherein when the HFM circuitry is enabled(i.e. HFM ON), the HFM drive current supplied to the VLD produces aspectral side-band components about the central characteristicwavelength of the VLD, reducing the coherence of the laser illuminationbeam as well as its coherence length.

Another object of the present invention is to provide alaser-despeckling PLIM which further comprises a flexible circuitsupporting (i) a VLD or IR laser diode (IRLD) and (ii) a HFM circuitrymounted in close proximity to the VLD or IRLD, and wherein the flexiblecircuit in turn is connected to a microprocessor-controlled currentdriver circuitry (e.g. controlled by a local control subsystem) realizedon a PC board.

Another object of the present invention is to provide alaser-despeckling PLIM which further comprises a flexible circuitsupporting (i) a VLD or IR laser diode (IRLD), (ii) a HFM circuitrymounted in close proximity to the VLD or IRLD, and (iii) amicroprocessor-controlled diode current driver circuitry which isconnected to the HFM circuitry and interfaced with a local controlsubsystem.

Another object of the present invention is to provide an optical beammultiplexor (OMUX) device, based on mirror and semi-transparentreflective coatings, deployable in a laser-despeckling PLIM so as toreduce (i) the coherence of the resulting planar/narrow-areaillumination beam generated therefrom, and (ii) thus the amount ofspeckle pattern noise observed at the image detection array of an imageformation and detection (IFD) subsystem employed in the digital imagecapturing and processing system in which the PLIM and IFD subsystem areintegrated.

Another object of the present invention is to provide a planar laserillumination array (PLIA) comprising a plurality of planar laserillumination modules (PLIMs), wherein each PLIM includes (i) a lasersource (e.g. VLD, IRLD, etc) driven preferably by HFM current drivecircuitry, (ii) a collimating lens (i.e. optics) disposed beyond thelaser source, (ii) an optical or laser beam multiplexor (OMUX) devicedisposed beyond the collimating lens, and (iv) a cylindrical-typeplanarizing-type illumination lens array disposed beyond the OMUX, andarranged as an integrated assembly so as to generate a plurality ofsubstantially planar coherence-reduced laser illumination beams (PLIBs)that form a composite substantially planar laser illumination beam(PLIB) having substantially reduced spatial/temporal coherence, whichsubstantially reduces the amount of speckle pattern noise observed atthe image detection array of the image formation and detection (IFD)subsystem while the composite PLIB illuminates an object during objectillumination and imaging operations within the digital image capturingand processing system in which subsystems cooperate.

Another object of the present invention is to provide a coplanarillumination and imaging subsystem employing such a PLIA design.

Another object of the present invention is to provide a coplanarillumination and imaging subsystem comprising a first plurality of VLDsand a second plurality of IRVDs mounted in a PLIA support block, towhich flexible HFM circuits are connected on one end, and to a PC boardon the other, forming an electrical interface with the correspondinglaser diode current drive circuits realized thereon.

Another object of the present invention is to provide a coplanarillumination and imaging subsystem comprising a first plurality of VLDsand a second plurality of IR VDs mounted in a PLIA support block, towhich flexible HFM and diode current drive circuits are connected.

Another object of the present invention is to provide a laser beam OMUXdevice comprising a single glass plate bearing reflective andsemi-reflective coatings to optically multiplex an input laser beam intomultiple spatial-coherence reduced output laser beams, which are thenplanarized into a composite substantially planar laser illumination beam(PLIB) by a multi-cylinder planarizing-type illumination lens arraydisposed in close proximity therewith.

Another object of the present invention is to provide a planar laserillumination array (PLIA) comprising an HFM diode current drive method,in combination with an optical despeckling method selected from thegroup consisting of the use of an optical beam multiplexor (OMUX)devices, and the use of a polarization despeckler device, so as to forma PLIA having an ultra-compact despeckler mechanism.

Another object of the present invention is to provide a laser beamdespeckling device comprising a three-sided prism and a ½ wave retarderplate disposed between a pair of mirrors arranged as shown, to opticallymultiplex an input laser beam into a single temporal-coherence reducedoutput laser beam, for subsequent planarization a multi-cylinderplanarizing-type illumination lens array disposed in close proximitytherewith.

Another object of the present invention is to provide a laser beamdespeckling device comprising a polarization beam splitter arrangedbetween a pair of prisms that forms an optical cube, and which supportsorthogonally-arranged mirrors each bearing a ¼ wave retarder, tooptically multiplex an input laser beam into a singletemporal/spatial-coherence reduced output laser beam, for subsequentplanarization a multi-cylinder planarizing-type illumination lens arraydisposed in close proximity therewith.

Another object of the present invention is to provide a laser beamdespeckling device comprising four mirrors, a ¼ wave retarder plate, abeam splitter arranged as shown, to optically multiplex andpolarization-encoded an input laser beam into twotemporal/spatial-coherence reduced output laser beams, for subsequentplanarization a multi-cylinder planarizing-type illumination lens arraydisposed in close proximity therewith;

Another object of the present invention is to provide apolarization-encoding based laser beam despeckling device comprising a ¼wave retarder plate disposed between a pair of glass plates bearingmirror and beam-splitter coatings as shown, to optically multiplex aninput laser beam into two spatial and temporal coherence reduced outputlaser beams, wherein the output beam is then subsequently planarized bya multi-cylinder planarizing-type illumination lens array disposed inclose proximity therewith.

Another object of the present invention is to provide a laser beamdespeckling device of the present invention comprising a ¼ wave retarderplate disposed between a pair of glass plates (multiplexors) bearingmirror and beam-splitter coatings as shown, to optically multiplex aninput laser beam into four spatial-coherence reduced output laser beams,for subsequent planarization by a multi-cylinder planarizing-typeillumination lens array disposed in close proximity therewith.

Another object of the present invention is to provide a multi-stagelaser beam despeckling device comprising a first laser beam despecklingmodule for optically multiplexing an input laser beam into atemporal/spatial coherence-reduced output laser beam, which is thentransmitted as an input laser beam to a second despeckling module forproducing an output spatial/temporal-coherence reduced laser beam, forsubsequent planarization by a multi-cylinder planarizing-typeillumination lens array disposed in close proximity therewith.

Another object of the present invention is to provide a planar laserillumination and imaging (PLIIM) module supporting arrays of VLDs and IRlaser diodes, and a field of view (FOV) forming optics and FOV foldingmirror for use with a digital linear image detecting array mounted on aPC board.

Another object of the present invention is to provide a planar laserillumination and imaging (PLIIM) module for producing a coplanarPLIB/FOV, comprising a PC board supporting a digital linear imagedetection chip (i.e. linear or narrow-area image sensor), HFM and diodecurrent drive circuitry, image capture and buffer circuitry, andsubsystem control circuitry.

Another object of the present invention is to provide such a planarlaser illumination and imaging (PLIIM) module further comprising a pairof PLIB/FOV folding mirrors arranged so as to direct the coplanarPLIB/FOV in a direction required by the system in which the PLIIM moduleis employed. Another object of the present invention is to provide aPOS-based digital image capturing and processing system embodying animproved speckle-reduction mechanism integrated with a plurality of VLDsand/or IRLDs (or other coherent illumination sources) that aredynamically managed to reduce illumination brightness to humans, whilemaintaining sufficient image contrast, during object illumination andimaging operations at the POS station.

Another object of the present invention is to provide such POS-baseddigital image capturing and processing system employing one or moreOMUX-based laser-despeckling modules that create a plurality of virtualspatially and/or temporally incoherent illumination sources from atleast one VLD or IRLD source.

Another object of the present invention is to provide such POS-baseddigital image capturing and processing system employing a planarillumination module (PLIM) that combines optical-based laser-despecklingtechniques with HFM diode current driving techniques so as to produceimproved apparatus for producing a composite coherence-reduced laserillumination beam for use in digital image formation and detectionoperations.

Another object of the present invention is to provide a linear-typedigital imaging system employing a wide-area illumination beam having adynamically controlled mixture of visible and IR spectral energy, so asto reduce illumination brightness at POS environments during systemoperation while achieving sufficiently high image contrast in captureddigital images of illuminated objects.

Another object of the present invention is to provide such linear-typedigital imaging system having a bioptical form factor with horizontaland vertical housing systems.

Another object of the present invention is to provide an area-typedigital imaging system employing a wide-area illumination beam having adynamically controlled mixture of visible and IR spectral energy, so asto reduce illumination brightness at POS environments during systemoperation while achieving sufficiently high image contrast in captureddigital images of illuminated objects.

Another object of the present invention is to provide such area-typedigital imaging system having a bioptical form factor with horizontaland vertical housing systems.

Another object of the present invention is to provide a hybridlinear-type and area-type digital imaging system employing a wide-areaillumination beam having a dynamically controlled mixture of visible andIR spectral energy, so as to reduce illumination brightness at POSenvironments during system operation while achieving sufficiently highimage contrast in captured digital images of illuminated objects.

Another object of the present invention is to provide such hybrid-typedigital imaging system having a bioptical form factor with horizontaland vertical housing systems.

Another object of the present invention is to provide anomni-directional digital image capturing and processing based bar codesymbol reading system comprising both a horizontal housing section witha first pair of laterally-spaced area-type illumination and imagingstations, and a vertical housing station with a second pair oflaterally-spaced area-type illumination and imaging stations, forsupporting both “pass-through” as well as “presentation” modes of barcode image capture.

Another object of the present invention is to provide such anomni-directional image capturing and processing based bar code symbolreading system, wherein the first pair of area-type illuminating andimaging stations are mounted within the horizontal section forprojecting a first pair of coextensive area-type illumination andimaging fields (i.e. zones) from its horizontal imaging window into the3D imaging volume of the system using both a dynamically/adaptivelycontrolled mixture of visible/IR illumination, and wherein the secondpair of area-type illumination and imaging stations are mounted in thevertical section for projecting a second pair of laterally-spacedarea-type illumination and imaging fields (i.e. zones) into the 3Dimaging volume of the system, also using both a dynamically/adaptivelycontrolled mixture of visible/IR illumination.

Another object of the present invention is to provide such anomni-directional image capturing and processing based bar code symbolreading system, wherein each coextensive area-type illumination andimaging station comprises a VLD/IRVD-based area illumination array, anarea-type image formation and detection subsystem, an image capturingand buffering subsystem, an automatic object motion/velocity sensingsubsystem, and a local control subsystem supporting a method ofdynamically/adaptively controlling visible/IR illumination.

These and other objects of the present invention will become apparenthereinafter and in the Claims to Invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more fully understand the Objects of the Present Invention,the following Detailed Description of the Illustrative Embodimentsshould be read in conjunction with the accompanying figure Drawings inwhich:

FIG. 1 is a perspective view of a retail point of sale (POS) station ofthe present invention employing an illustrative embodiment of theomni-directional image capturing and processing based bar code symbolreading system of the present invention, shown integrated with anelectronic weight scale, an RFID reader and magnet-stripe card reader,and having thin, tablet-like form factor for compact mounting in thecountertop surface of the POS station;

FIG. 2 is a first perspective view of the omni-directional imagecapturing and processing based bar code symbol reading system of thepresent invention shown removed from its POS environment in FIG. 1, andprovided with an imaging window protection plate (mounted over a glasslight transmission window) and having a central X aperture pattern and apair of parallel apertures aligned parallel to the sides of the system,for the projection of coplanar illumination and imaging planes from acomplex of coplanar illumination and imaging stations mounted beneaththe imaging window of the system;

FIG. 2A is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system shown in FIG. 2,wherein the apertured imaging window protection plate is simply removedfrom its glass imaging window for cleaning the glass imaging window,during routine maintenance operations at POS station environments;

FIG. 2B is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system shown in FIG. 2,wherein the image capturing and processing module (having a thin tabletform factor) is removed from the electronic weigh scale module duringmaintenance operations, revealing the centrally located load cell, andthe touch-fit electrical interconnector arrangement of the presentinvention that automatically establishes all electrical interconnectionsbetween the two modules when the image capturing and processing moduleis placed onto the electronic weigh scale module, and its electronicload cell bears the weight of the image capturing and processing module;

FIG. 2C is an elevated side view of the omni-directional image capturingand processing based bar code symbol reading system shown in FIG. 2B,wherein the image capturing and processing module is removed from theelectronic weigh scale module during maintenance operations, revealingthe centrally located load cell, and the touch-fit electricalinterconnector arrangement of the present invention that automaticallyestablishes all electrical interconnections between the two modules whenthe image capturing and processing module is placed onto the electronicweigh scale module, and its electronic load cell bears substantially allof the weight of the image capturing and processing module;

FIG. 2D is an elevated side view of the omni-directional image capturingand processing based bar code symbol reading system shown in FIG. 22,wherein side wall housing skirt is removed for illustration purposes toreveal how the load cell of the electronic weigh scale module directlybears all of the weight of the image capturing and processing module(and any produce articles placed thereon during weighing operations)while the touch-fit electrical interconnector arrangement of the presentinvention automatically establishes all electrical interconnectionsbetween the two modules;

FIG. 3A is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, showing afirst coplanar illumination and imaging plane being generated from afirst coplanar illumination and imaging station, and projected through afirst side aperture formed in the imaging window protection plate of thesystem, and wherein the coplanar illumination and imaging plane of thestation is composed of several segments which can be independently andelectronically controlled under the local control subsystem of thestation;

FIG. 3B is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, showing asecond coplanar illumination and imaging plane being generated from asecond coplanar illumination and imaging station, and projected througha first part of the central X aperture pattern formed in the imagingwindow protection plate of the system;

FIG. 3C is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, showing athird coplanar illumination and imaging plane being generated from athird coplanar illumination and imaging station, and projected through asecond part of the central X aperture pattern formed in the imagingwindow protection plate of the system;

FIG. 3D is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, showing afourth coplanar illumination and imaging plane being generated from afourth coplanar illumination and imaging station, and projected througha third part of the central X aperture pattern formed in the imagingwindow protection plate of the system;

FIG. 3E is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, showing afifth coplanar illumination and imaging plane being generated from afifth coplanar illumination and imaging station, and projected through afourth part of the central X aperture pattern formed in the imagingwindow protection plate of the system;

FIG. 3F is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, showing asixth coplanar illumination and imaging plane being generated from asixth coplanar illumination and imaging station, and projected through asecond side aperture formed in the imaging window protection plate ofthe system;

FIG. 3G is a first elevated side view of the omni-directional imagecapturing and processing based bar code symbol reading system of FIG. 2,showing all of its six coplanar illumination and imaging planes beingsubstantially simultaneously generated from the complex of coplanarillumination and imaging stations, and projected through the imagingwindow of the system, via the apertures in its imaging window protectionplate, and intersecting within a 3-D imaging volume supported above theimaging window;

FIG. 3H is a second elevated side view of the omni-directional imagecapturing and processing based bar code symbol reading system of FIG. 2,showing all of its six coplanar illumination and imaging planes beingsubstantially simultaneously projected through the imaging window of thesystem, via the apertures in its imaging window protection plate;

FIG. 4A is a perspective view of theprinted-circuit(PC)-board/optical-bench associated with theomni-directional image capturing and processing based bar code symbolreading system of FIG. 2, shown with the top portion of its housing,including its imaging window and window protection plate, removed forpurposes of revealing the coplanar illumination and imaging stationsmounted on the optical bench of the system and without these stationsgenerating their respective coplanar illumination and imaging planes;

FIG. 4B is a plane view of the optical bench associated with theomni-directional image capturing and processing based bar code symbolreading system of FIG. 2, shown with the top portion of its housing,including its imaging window and window protection plate, removed forpurposes of revealing the coplanar illumination and imaging stationsmounted on the optical bench of the system while these stations aregenerating their respective coplanar illumination and imaging planes;

FIG. 4C is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, shownwith the top portion of its housing, including its imaging window andwindow protection plate removed, wherein the first coplanar illuminationand imaging plane is shown generated from the first coplanarillumination and imaging station and projected through the first sideaperture formed in the imaging window protection plate of the system;

FIG. 4D is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, shownwith the top portion of its housing, including its imaging window andwindow protection plate removed, wherein the second coplanarillumination and imaging plane is shown generated the second coplanarillumination and imaging station and projected through the first part ofthe central X aperture pattern formed in the imaging window protectionplate of the system;

FIG. 4E is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, shownwith the top portion of its housing, including its imaging window andwindow protection plate removed, wherein the third coplanar illuminationand imaging plane is shown generated from the third coplanarillumination and imaging station and projected through the second partof the central X aperture pattern formed in the imaging windowprotection plate of the system;

FIG. 4F is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, shownwith the top portion of its housing, including its imaging window andwindow protection plate removed, wherein the fourth coplanarillumination and imaging plane is shown generated from the fourthcoplanar illumination and imaging station, and projected through thethird part of the central X aperture pattern formed in the imagingwindow protection plate of the system;

FIG. 4G is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, shownwith the top portion of its housing, including its imaging window andwindow protection plate removed, wherein the fifth coplanar illuminationand imaging plane is shown generated from the fifth coplanarillumination and imaging station, and projected through the fourth partof the central X aperture pattern formed in the imaging windowprotection plate of the system;

FIG. 4H is a perspective view of the omni-directional image capturingand processing based bar code symbol reading system of FIG. 2, shownwith the top portion of its housing, including its imaging window andwindow protection plate removed, wherein the sixth coplanar illuminationand imaging plane is shown generated from the sixth coplanarillumination and imaging station, and projected through the second sideaperture formed in the imaging window protection plate of the system;

FIG. 5A is a block schematic representation of a generalized embodimentof the omni-directional image capturing and processing system of thepresent invention, comprising a complex of coplanar illuminating andlinear imaging stations, constructed using VLD-based or LED-basedillumination arrays and linear and/area type image sensing arrays, andreal-time object motion/velocity detection techniques for enablingintelligent automatic illumination control within its 3D imaging volume,as well as automatic image formation and capture along each coplanarillumination and imaging plane therewithin;

FIG. 5B is a block schematic representation of a coplanar or coextensiveillumination and imaging subsystem (i.e. station) employed in thegeneralized embodiment of the omni-directional image capturing andprocessing system of FIG. 5A, comprising an image formation anddetection subsystem having an image sensing array and optics providing afield of view (FOV) on the image sensing array, an illuminationsubsystem producing a field of illumination that is substantiallycoplanar or coextensive with the FOV of the image sensing array, animage capturing and buffering subsystem for capturing and bufferingimages from the image sensing array, an automatic object motion/velocitydetection subsystem for automatically detecting the motion and velocityof an object moving through at least a portion of the FOV of the imagesensing array, and a local control subsystem for controlling theoperations of the subsystems within the illumination and imagingstation;

FIG. 5C is a block schematic representation of a coplanar laserillumination and imaging subsystem (i.e. station) employed in thegeneralized embodiment of the omni-directional image capturing andprocessing system of FIG. 5A, comprising (i) an image formation anddetection (IFD) subsystem having a linear (1D) image sensing array (or2D image sensing array with a narrow-area region activated forphoto-integration) and optics providing a field of view (FOV) on theimage sensing array, an spectral-mixing based illumination subsystemproducing a first field of visible illumination (produced from an arrayof VLDs) and a second field of invisible illumination (produced from anarray of IR LDs) that spatially overlap and spatially/temporallyintermix with each other while having a preset relative power ratio(VIS/IR), and are substantially coplanar or coextensive with the FOV ofthe image sensing array, an integrated laser despeckling mechanismassociated the IFD subsystem, (ii) an image capturing and bufferingsubsystem for capturing and buffering images from the image sensingarray, (iii) an automatic object motion/velocity detection subsystem forautomatically detecting the motion and velocity of an object movingthrough at least a portion of the FOV of the image sensing array, and(iv) a local control subsystem for controlling the operations of thesubsystems within the illumination and imaging station;

FIG. 5D is a block schematic representation of a coplanar laserillumination and imaging subsystem (i.e. station) which can be employedany digital image capturing and processing system of the presentinvention and comprises: an image formation and detection (IFD)subsystem having a linear (1D) image sensing array (or 2D image sensingarray with a narrow-area region activated for photo-integration) andoptics providing a field of view (FOV) on the image sensing array; anspectral-mixing based illumination subsystem producing a first field ofvisible illumination (produced from an array of VLDs) and a second fieldof invisible illumination (produced from an array of IR LDs) thatspatially overlap and spatially/temporally intermix with each otherwhile having a preset relative power ratio (VIS/IR), and aresubstantially coplanar or coextensive with the FOV of the image sensingarray; an integrated laser despeckling mechanism associated the IFDsubsystem using the high-frequency modulation HFM techniques of thepresent invention disclosed in FIGS. 5H through 5N, and opticalmultiplexing (OMUX) techniques of the present invention disclosed inFIGS. 5O through 5X7; an image capturing and buffering subsystem forcapturing and buffering images from the image sensing array; anautomatic object motion/velocity detection subsystem for automaticallydetecting the motion and velocity of an object moving through at least aportion of the FOV of the image sensing array; and a local controlsubsystem for controlling the operations of the subsystems within theillumination and imaging station;

FIG. 5E1 is a block schematic representation of a coplanar laserillumination and imaging subsystem (i.e. station) which can be employedany digital image capturing and processing system of the presentinvention and comprises: an image formation and detection (IFD)subsystem having a linear (1D) image sensing array (or 2D image sensingarray with a narrow-area region activated for photo-integration) andoptics providing a field of view (FOV) on the image sensing array; anspectral-mixing based illumination subsystem producing a first field ofvisible illumination (produced from an array of VLDs) and a second fieldof invisible illumination (produced from an array of IR LDs) thatspatially overlap and spatially/temporally intermix with each otherwhile having a adaptively/dynamically set relative power ratio (VIS/IR),and are substantially coplanar or coextensive with the FOV of the imagesensing array; an integrated laser de-speckling mechanism associated theIFD subsystem as disclosed in WIPO Publication No. WO/2002/043195 or inthe present Specification; an image capturing and buffering subsystemfor capturing and buffering images from the image sensing array; anautomatic object motion/velocity detection subsystem for automaticallydetecting the motion and velocity of an object moving through at least aportion of the FOV of the image sensing array; and a local controlsubsystem for controlling the operations of the subsystems within theillumination and imaging station;

FIG. 5E2 is a flow chart illustrating the steps involved in the methodof adaptively/dynamically controlling the spectral composition of theplanar illumination beam produced from the illumination subsystem of thecoplanar laser illumination and imaging subsystem (i.e. station)illustrated in FIG. 5E1;

FIG. 5F1 is a block schematic representation of a coplanar laserillumination and imaging subsystem (i.e. station) which can be employedany digital image capturing and processing system of the presentinvention and comprises: an image formation and detection (IFD)subsystem having a linear (1D) image sensing array (or 2D image sensingarray with a narrow-area region activated for photo-integration) andoptics providing a field of view (FOV) on the image sensing array; anspectral-mixing based illumination subsystem producing a first field ofvisible illumination (produced from an array of VLDs) and a second fieldof invisible illumination (produced from an array of IR LDs) thatspatially overlap and spatially/temporally intermix with each otherwhile having a adaptively/dynamically set relative power ratio (VIS/IR),and are substantially coplanar or coextensive with the FOV of the imagesensing array; an integrated laser de-speckling mechanism associated theIFD subsystem using the high-frequency modulation HFM techniques of thepresent invention disclosed in FIGS. 5H through 5N, and opticalmultiplexing (OMUX) techniques of the present invention disclosed inFIGS. 5O through 5X7; an image capturing and buffering subsystem forcapturing and buffering images from the image sensing array; anautomatic object motion/velocity detection subsystem for automaticallydetecting the motion and velocity of an object moving through at least aportion of the FOV of the image sensing array; and a local controlsubsystem for controlling the operations of the subsystems within theillumination and imaging station;

FIG. 5F2 is a flow chart illustrating the steps involved in the methodof adaptively/dynamically controlling the spectral composition of theplanar illumination beam produced from the illumination subsystem of thecoplanar laser illumination and imaging subsystem (i.e. station)illustrated in FIG. 5F1;

FIG. 5G1 is a block schematic representation of a coextensive area-typeillumination and imaging subsystem (i.e. station) which can be employedany digital image capturing and processing system of the presentinvention and comprises: an image formation and detection (IFD)subsystem having an area-type (2D) image sensing array and opticsproviding a field of view (FOV) on the image sensing array; anspectral-mixing based illumination subsystem producing a first field ofincoherent visible illumination (produced from an array of visible LEDs)and a second field of incoherent invisible illumination (produced froman array of IR LEDs) that spatially overlap and spatially/temporallyintermix with each other while having an adaptively/dynamically setrelative power ratio (VIS/IR), and are substantially coplanar orcoextensive with the FOV of the image sensing array; an image capturingand buffering subsystem for capturing and buffering 2D images from theimage sensing array; an automatic object motion/velocity detectionsubsystem for automatically detecting the motion and velocity of anobject moving through at least a portion of the FOV of the image sensingarray; and a local control subsystem for controlling the operations ofthe subsystems within the illumination and imaging station;

FIG. 5G2 is a flow chart illustrating the steps involved in the methodof adaptively/dynamically controlling the spectral composition of theplanar illumination beam produced from the illumination subsystem of thecoplanar illumination and imaging subsystem (i.e. station) illustratedin FIG. 5G1;

FIG. 5H is a schematic block diagram of the HFM-OMUX based IlluminationSubsystem of the present invention, which produces adynamically/adaptively managed mixture of invisible and visibleillumination energy generated by a linear array of threedynamically/adaptively driven VLD-Based Planar Laser IlluminationModules (PLIMs), i.e. VLD-Based Planar Laser Illumination Array (PLIA),and three dynamically/adaptively driven channels IRLD-Based PLIMs, i.e.IRLD-based PLIA, operated under the control of the local controlsubsystem, in response to control data produced by the image processingsubsystem running the spectral-mixture control algorithm of the presentinvention (FIGS. 5E2, 5F2 and 5G2);

FIG. 5I1 is a schematic block diagram illustrating a single HFM-OMUXbased PLIM of the present invention depicted in FIG. 5H, showing itsVLD, HFM circuitry and its current drive circuitry, with the HFM controlsignal OFF to disable high frequency modulation of the drive currentsupplied to the VLD;

FIG. 5I2 is a schematic block diagram illustrating a single HFM-OMUXbased PLIM of the present invention depicted in FIG. 5H, showing itsVLD, HFM circuitry and its current drive circuitry, with the HFM controlsignal ON to enable high frequency modulation of the drive currentsupplied to the VLD;

FIG. 5J1 is a graphical representation of a screen shot of the opticalspectrum emitted from a HFM-OMUX based PLIM of the present inventionemployed in the Illumination Subsystem of FIG. 5H, wherein the highfrequency modulation (HFM) circuitry is disabled (i.e. HFM OFF) so thatthe drive current supplied to the VLD (i.e. HFM OFF) produces a singlenarrow-band peak about the characteristic wavelength of the VLD;

FIG. 5J2 is a graphical representation of a screen shot of the opticalspectrum emitted from a HFM-OMUX based PLIM of the present inventionemployed in the illumination subsystem of FIG. 5H, wherein the highfrequency modulation (HFM) circuitry is enabled (i.e. HFM ON) so thatthe HFM drive current supplied to the VLD (i.e. HFM OFF) produces aspectral sideband components about the central characteristic wavelengthof the VLD, reducing the coherence of the laser illumination beam aswell as its coherence length;

FIG. 5K1 is a schematic representation of a first illustrativeembodiment of a single HFM-OMUX based PLIM of the present invention thatcan be employed in the HFM-OMUX based illumination subsystem of FIG. 5H,and shown comprising a flexible circuit as shown in FIGS. 5N1 and 5N2,and supporting (i) a VLD or IR laser diode (IRLD) and (ii) a HFMcircuitry mounted in close proximity to the VLD or IRLD, and wherein theflexible circuit in turn is connected to a microprocessor-controlledcurrent driver circuitry (e.g. controlled by the local controlsubsystem) realized on a PC board;

FIG. 5K2 is a schematic representation of a second illustrativeembodiment of a single HFM-OMUX based PLIM of the present invention thatcan be employed in the HFM-OMUX based illumination subsystem of FIG. 5H,and shown comprising a flexible circuit as shown in FIGS. 5N1 and 5N2,and supporting (i) a VLD or IR laser diode (IRLD), (ii) a HFM circuitrymounted in close proximity to the VLD or IRLD, and (iii) amicroprocessor-controlled current driver circuitry which is connected tothe HFM circuitry and interfaced with the local control subsystem;

FIG. 5L is a schematic diagram of the HFM circuitry of the presentinvention, employed in each PLIM of the HFM-OMUX based illuminationsubsystem of FIG. 5H;

FIGS. 5M1 and 5M2, taken together, set forth a schematic diagram of thecurrent driver circuitry of the present invention, employed in each PLIMof the HFM based illumination subsystem of FIG. 5H;

FIG. 5N1 is a schematic representation on the front side of the flexiblecircuit schematically illustrated in FIG. 5K1, and employed in each PLIMof the HFM-OMUX Based Illumination Subsystem of FIG. 5H;

FIG. 5N2 is a schematic representation on the back side of the flexiblecircuit schematically illustrated in FIG. 5K1, and employed in each PLIMof the HFM-OMUX based illumination subsystem of FIG. 5H;

FIG. 5N3 is a schematic representation on the front side of the flexiblecircuit schematically illustrated in FIG. 5K2, and employed in each PLIMof the HFM-OMUX Based Illumination Subsystem of FIG. 5H;

FIG. 5N4 is a schematic representation on the back side of the flexiblecircuit schematically illustrated in FIG. 5K2, and employed in each PLIMof the HFM-OMUX based illumination subsystem of FIG. 5H;

FIG. 5O is a schematic representation of a first illustrative embodimentof the optical despeckling device of the present invention, based onoptical beam multiplexing principles and deployable in each PLIM of theHFM-OMUX based illumination subsystem of FIG. 5P, so as to reduce (i)the coherence of the resulting planar/narrow-area illumination beamgenerated therefrom, and (ii) thus the amount of speckle pattern noiseobserved at the image detection array of the image formation anddetection (IFD) subsystem in the digital image capturing and processingsystem in which subsystems are contained;

FIG. 5P is a schematic representation of a first illustrative embodimentof the planar laser illumination array (PLIA) of the present invention,comprising a plurality of planar laser illumination modules (PLIMs) asshown in FIG. 5O, wherein each PLIM includes (i) a laser source (e.g.VLD, IR LD, etc) driven preferably by the HFM current drive circuitry ofthe present invention shown in FIGS. 5K through 5M, (ii) a collimatinglens (i.e. optics) disposed beyond the laser source, (ii) a laser beamoptical multiplexor (OMUX) device of the present invention disposedbeyond the collimating lens, and (iv) a cylindrical-typeplanarizing-type illumination lens array disposed beyond the OMUX, andarranged as an integrated assembly so as to generate a plurality ofsubstantially planar coherence-reduced laser illumination beams (PLIBs)that form a composite substantially planar laser illumination beam(PLIB) having substantially reduced spatial/temporal coherence, whichsubstantially reduces the amount of speckle pattern noise observed atthe image detection array of the image formation and detection (IFD)subsystem (during the photo-integration period of the image detectionarray) as the composite PLIB illuminates an object during objectillumination and imaging operations;

FIG. 5Q is a schematic representation of first illustrativeimplementation of the coplanar illumination and imaging subsystemillustrated in FIGS. 5E1 and 5E2, employing the PLIA illustrated inFIGS. 5O and 5P;

FIG. 5R is plan view of the coplanar illumination and imaging subsystemillustrated in FIG. 5Q;

FIG. 5S is a first elevated side view of the coplanar illumination andimaging subsystem illustrated in FIG. 5Q;

FIG. 5T is an elevated front view of the coplanar illumination andimaging subsystem illustrated in FIG. 5Q;

FIG. 5U is a second perspective view of the coplanar illumination andimaging subsystem illustrated in FIG. 5Q, showing three VLDs and threeIRVDs mounted in the PLIA support, to which the flexible HFM circuits ofthe present invention illustrated in FIGS. 5K1 through 5N4 are connectedon one end, and to PC board on the other, forming an electricalinterface with the corresponding laser diode current drive circuitsrealized thereon, and described in FIG. 5M;

FIG. 5V is a schematic diagram of a second illustrative embodiment ofthe laser beam despeckling device of the present invention, shownconstructed as an OMUX-based device comprising a single glass platebearing reflective and semi-reflective coatings to optically multiplexan input laser beam into multiple spatial-coherence reduced output laserbeams, which are then planarized into composite substantially planarlaser illumination beam (PLIB) by a multi-cylinder planarizing-typeillumination lens array disposed in close proximity therewith;

FIG. 5W is a schematic representation of a planar laser illuminationarray (PLIA) according to the present invention employing the HFM diodecurrent drive method of the present invention illustrated in FIGS. 5Hthrough 5N4, in combination with any laser beam despeckling method ofthe present invention, including the optical beam multiplexor (OMUX)despeckler devices illustrated in FIGS. 5O and 5V, as well as thepolarization-encoding despeckler devices illustrated in FIGS. 5W1through 5W6, so as to form a PLIA having an ultra-compact “super”despeckler mechanism;

FIG. 5W1 shows a third illustrative embodiment of the laser beamdespeckling device of the present invention, constructed as apolarization-encoding OMUX device comprising a three-sided prism and a ½wave retarder plate disposed between a pair of mirrors arranged asshown, to optically multiplex an input laser beam into a singletemporal-coherence reduced output laser beam, for subsequentplanarization a multi-cylinder planarizing-type illumination lens arraydisposed in close proximity therewith;

FIG. 5W2 shows a fourth illustrative embodiment of the laser beamdespeckling device of the present invention, constructed aspolarization-encoding OMUX device comprising a polarization beamsplitter arranged between a pair of prisms that forms and optical cube,and which supports orthogonally-arranged mirrors each bearing a ¼ waveretarder as shown, to optically multiplex an input laser beam into asingle temporal/spatial-coherence reduced output laser beam, forsubsequent planarization a multi-cylinder planarizing-type illuminationlens array disposed in close proximity therewith;

FIG. 5W3 is a schematic diagram of a fifth illustrative embodiment ofthe laser beam despeckling device of the present invention, constructedas a polarization-encoding OMUX device comprising four mirrors, a ¼ waveretarder plate, a beam splitter arranged as shown, to opticallymultiplex and polarization-encoded an input laser beam into twotemporal/spatial-coherence reduced output laser beams, for subsequentplanarization a multi-cylinder planarizing-type illumination lens arraydisposed in close proximity therewith;

FIG. 5W4 shows an embodiment of a polarization-encoding based laser beamdespeckling device, constructed as a polarization encoding OMUX devicecomprising a ¼ wave retarder plate disposed between a pair of glassplates bearing mirror and beam-splitter coatings as shown, to opticallymultiplex an input laser beam into two spatial and temporal coherencereduced output laser beams, and wherein the output beam is thensubsequently planarized by a multi-cylinder planarizing-typeillumination lens array disposed in close proximity therewith;

FIG. 5W5 is a schematic diagram of a seventh illustrative embodiment ofthe laser beam despeckling device of the present invention, similar tothe device of FIG. 5W4, and shown constructed as a polarization-encodingOMUX device comprising a ¼ wave retarder plate disposed between a pairof glass plates (multiplexors) bearing mirror and beam-splitter coatingsas shown, to optically multiplex an input laser beam into fourspatial-coherence reduced output laser beams, for subsequentplanarization a multi-cylinder planarizing-type illumination lens arraydisposed in close proximity therewith, and wherein the opticalmultiplexor can extended with the addition of another beam splittingcoating to further double the number of laser beams internally producedfor ultimate recombination;

FIG. 5W6 is a schematic diagram of a eighth illustrative embodiment of amulti-stage laser beam despeckling device of the present invention,shown constructed as an OMUX-based optical subsystem comprising (i) afirst laser beam despeckling module as shown in FIG. 5W2 to opticallymultiplex an input laser beam into a temporal/spatial coherence reducedoutput laser beam, and (ii) a second laser beam despeckling module asshown in FIG. 5O for receiving the output laser beam from the firstlaser beam despeckling device, and producing, as output, aspatial/temporal-coherence reduced laser beam, for subsequentplanarization a multi-cylinder planarizing-type illumination lens arraydisposed in close proximity therewith;

FIG. 5X1 is a first perspective view of the HFM-OMUX based planar laserillumination and imaging (PLIIM) module of the present invention, shownremoved from the PC board supporting the digital image detection arraysensor chip as illustrated in FIG. 5X7 5Y, and supporting both VLDs andIR laser diodes, a field of view (FOV) forming optics and a FOV foldingmirror for use with the digital image detecting array mounted on the PCboard;

FIG. 5X2 is an elevated side view of the planar laser illumination andimaging (PLIIM) module of the present invention depicted in FIG. 5X1,and showing it composite planar illumination beam (PLIB) arranged in acoplanar relationship with the central plane of the FOV of its imageformation optics assembly;

FIG. 5X3 is a perspective, partially-exploded view of the planar laserillumination and imaging (PLIIM) module of the present inventiondepicted in FIG. 5X1, shown with its housing structure removed from itsPC board, and its adjustable PLIMs removed from the mounting aperturesformed in its housing structure, supporting the FOV mirror and FOVforming optics assembly;

FIG. 5X4 is a perspective view of the planar laser illumination andimaging (PLIIM) module of the present invention depicted in FIG. 5X1,shown mounted on its PC board shown supporting the digital linear imagedetection chip (i.e. linear or narrow-area image sensor), HFM andcurrent drive circuitry, image capture and buffer circuitry, subsystemcontrol circuitry (e.g. programmed micro-controller etc);

FIG. 5Y is a perspective view the planar laser illumination and imaging(PLIIM) module of the present invention depicted in FIG. 5X1, shownarranged with a pair of PLIB/FOV folding mirrors used to direct thecoplanar PLIB/FOV in a direction required by the system in which thePLIIM module is employed;

FIG. 6 is a perspective view of the first illustrative embodiment of theomni-directional image capturing and processing based bar code symbolreading system of the present invention, shown removed from its POSenvironment, and with one coplanar illumination and imaging plane beingprojected through an aperture in its imaging window protection plate,along with a plurality of object motion/velocity detection field ofviews (FOVs) that are spatially co-incident with portions of the fieldof view (FOV) of the linear imaging array employed in the coplanarillumination and imaging station generating the projected coplanarillumination and imaging plane;

FIG. 6A is a perspective view of a first design for each coplanarillumination and imaging station that can be employed in theomni-directional image capturing and processing based bar code symbolreading system of FIG. 6, wherein a linear array of VLDs or LEDs areused to generate a substantially planar illumination beam (PLIB) fromthe station that is coplanar with the field of view of the linear (1D)image sensing array employed in the station, and wherein three (3)high-speed imaging-based motion/velocity sensors (i.e. detectors) aredeployed at the station for the purpose of (i) detecting whether or notan object is present within the FOV at any instant in time, and (ii)detecting the motion and velocity of objects passing through the FOV ofthe linear image sensing array and controlling camera parameters inreal-time, including the clock frequency of the linear image sensingarray;

FIG. 6B is a block schematic representation of the omni-directionalimage capturing and processing based bar code symbol reading system ofFIG. 6, wherein a complex of coplanar illuminating and linear imagingstations, constructed using VLD-based or LED-based illumination arraysand linear (CMOS-based) image sensing arrays, as shown in FIG. 6A, andimaging-based object motion/velocity sensing and intelligent automaticillumination control within the 3D imaging volume, and automatic imageformation and capture along each coplanar illumination and imaging planetherewithin;

FIG. 6C is a block schematic representation of one of the coplanarillumination and imaging stations employed in the system embodiment ofFIG. 6B, showing its planar illumination array (PLIA), its linear imageformation and detection subsystem, its image capturing and bufferingsubsystem, its high-speed imaging based object motion/velocity detecting(i.e. sensing) subsystem, and its local control subsystem;

FIG. 6D is a schematic representation of an exemplary high-speedimaging-based motion/velocity sensor employed in the high-speed imagingbased object motion/velocity detecting (i.e. sensing) subsystem of thecoplanar illumination and imaging station of FIG. 6A;

FIG. 6E1 is a block schematic representation of the high-speedimaging-based object motion/velocity detection subsystem employed ateach coplanar illumination and imaging station supported by the system,shown comprising an area-type image acquisition subsystem and anembedded digital signal processing (DSP) chip to support high-speedlocally digital image capture and (local) processing operations requiredfor real-time object motion/velocity detection;

FIG. 6E2 is a high-level flow chart describing the steps involved in theobject motion/velocity detection process carried out at each coplanarillumination and imaging station supported by the system of the presentinvention;

FIG. 6E3 is a schematic representation illustrating the automaticdetection of object motion and velocity at each coplanar illuminationand imaging station in the system of the present invention, employing animaging-based object motion/velocity sensing subsystem having a 2D imagesensing array;

FIG. 6E4 is a schematic representation illustrating the automaticdetection of object motion and velocity at each coplanar illuminationand imaging station in the system of the present invention depicted inFIG. 2, employing an imaging-based object motion/velocity sensingsubsystem having a 1D image sensing array;

FIG. 6F1 is a state transition diagram for the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIGS. 2 and 6C, running the system control program described in FIGS.6G1A and 6G1B;

FIG. 6F2 is a state transition diagram for the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIGS. 2 and 6C, running the system control program described in FIGS.6G2A and 6G2B;

FIG. 6F3 is a state transition diagram for the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIGS. 2 and 6C, running the system control program described in FIGS.6G2A and 6G2B;

FIGS. 6G1A and 6G1B, taken together, set forth a high-level flow chartdescribing the operations (i.e. tasks) that are automatically performedduring the state control process of FIG. 6F1 carried out within theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 2 and 6E4, employinglocally-controlled object motion/velocity detection in each coplanarillumination and imaging subsystem of the system;

FIGS. 6G2A and 6G2B, taken together, set forth a high-level flow chartdescribing the operations (i.e. tasks) that are automatically performedduring the state control process of FIG. 6F2 carried out within theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 2 and 6E4, employinglocally-controlled object motion/velocity detection in each coplanarillumination and imaging subsystem of the system, withglobally-controlled over-driving of nearest-neighboring stations;

FIGS. 6G3A and 6G3B, taken together, set forth a high-level flow chartdescribing the operations (i.e. tasks) that are automatically performedduring the state control process of FIG. 6F3 carried out within theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 2 and 6E4, employinglocally-controlled object motion/velocity detection in each coplanarillumination and imaging subsystem of the system, withglobally-controlled over-driving of all-neighboring stations upon thedetection of an object by one of the coplanar illumination and imagingstations;

FIG. 6H is a schematic diagram describing an exemplary embodiment of acomputing and memory architecture platform for implementing theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 2 and 6C;

FIG. 7A is a perspective view of a third illustrative embodiment of theomni-directional image capturing and processing based bar code symbolreading system of the present invention installed in the countertopsurface of a retail POS station, shown comprising a complex of coplanarillumination and imaging stations projecting a plurality of coplanarillumination and imaging planes through the 3D imaging volume of thesystem, and plurality of globally-implemented imaging-based objectmotion and velocity detection subsystems continually sensing thepresence, motion and velocity of objects within the 3-D imaging volume;

FIG. 7A1 is a schematic representation of the omni-directional imagecapturing and processing based bar code symbol reading system of FIG.7A, wherein each coplanar illumination and imaging subsystem employs alinear array of VLDs or LEDs for generating a substantially planarillumination beam (PLIB) that is coplanar with the field of view of itslinear (1D) image sensing array, and wherein a plurality ofglobally-controlled high-speed imaging-based motion/velocity subsystemsare deployed in the system for the purpose of (i) detecting whether ornot an object is present within the 3-D imaging volume of the system atany instant in time, and (ii) detecting the motion and velocity ofobjects passing therethrough and controlling camera parameters at eachstation in real-time, including the clock frequency of the linear imagesensing arrays;

FIG. 7A2 is a block schematic representation of one of the coplanarillumination and imaging stations employed in the system embodiment ofFIG. 7A1, showing its planar illumination array (PLIA), its linear imageformation and detection subsystem, its image capturing and bufferingsubsystem, and its local control subsystem;

FIG. 7A3 is a block schematic representation of the high-speedimaging-based object motion/velocity detection subsystem employed in thesystem of FIG. 7A1, shown comprising an area-type image acquisitionsubsystem and an embedded digital signal processing (DSP) chip tosupport high-speed digital image capture and (global) processingoperations required for real-time object motion/velocity detectionthrough the 3D imaging volume of the system;

FIG. 7A4 is a high-level flow chart describing the steps associated withthe object motion and velocity detection process carried out in theobject motion/velocity detection subsystems globally implemented in thesystem of FIGS. 7A and 7A1;

FIG. 7B is a perspective view of a fourth illustrative embodiment of theomni-directional image capturing and processing based bar code symbolreading system of the present invention installed in the countertopsurface of a retail POS station, shown comprising a complex of coplanarillumination and imaging stations projecting a plurality of coplanarillumination and imaging planes through the 3D imaging volume of thesystem, and plurality of globally-implemented IR Pulse-Doppler LIDARbased object motion and velocity detection subsystems continuallysensing the presence, motion and velocity of objects within the 3-Dimaging volume;

FIG. 7B1 is a schematic representation of the omni-directional imagecapturing and processing based bar code symbol reading system of FIG.7B, wherein each coplanar illumination and imaging subsystem employs alinear array of VLDs or LEDs for generating a substantially planarillumination beam (PLIB) that is coplanar with the field of view of itslinear (1D) image sensing array, and wherein a plurality ofglobally-controlled high-speed IR Pulse-Doppler LIDAR-basedmotion/velocity subsystems are deployed in the system for the purpose of(i) detecting whether or not an object is present within the 3-D imagingvolume of the system at any instant in time, and (ii) detecting themotion and velocity of objects passing therethrough and controllingcamera parameters at each station in real-time, including the clockfrequency of the linear image sensing arrays;

FIG. 7B2 is a block schematic representation of one of the coplanarillumination and imaging stations employed in the system embodiment ofFIG. 7B1, showing its planar illumination array (PLIA), its linear imageformation and detection subsystem, its image capturing and bufferingsubsystem, and its local control subsystem;

FIG. 7C is a block schematic representation of the high-speed IRPulse-Doppler LIDAR-based object motion/velocity detection subsystememployed in the system of FIG. 7B1, shown comprising an area-type imageacquisition subsystem and an embedded digital signal processing (DSP)ASIC chip to support high-speed digital signal processing operationsrequired for real-time object motion/velocity detection through the 3Dimaging volume of the system;

FIG. 7D is a schematic representation of an preferred implementation ofthe high-speed IR Pulse-Doppler LIDAR-based object motion/velocitydetection subsystem employed in the system of FIG. 8B1, wherein a pairof pulse-modulated IR laser diodes are focused through optics andprojected into the 3D imaging volume of the system for sensing thepresence, motion and velocity of objects passing therethrough inreal-time using IR Pulse-Doppler LIDAR techniques;

FIG. 7E is a high-level flow chart describing the steps associated withthe object motion and velocity detection process carried out in theobject motion/velocity detection subsystems globally implemented in thesystem of FIGS. 7B through 7D;

FIG. 7F is a state transition diagram for the omni-directional imagecapturing and processing based bar code symbol reading system in FIG.7B, describing the state transitions that the system undergoes duringoperation;

FIG. 7G is a high-level flow chart describing the operations that areautomatically performed during the state control process carried outwithin the omni-directional image capturing and processing based barcode symbol reading system described in FIG. 7B;

FIG. 7H is a schematic diagram describing an exemplary embodiment of acomputing and memory architecture platform for implementing theomni-directional image capturing and processing based bar code symbolreading system described FIG. 7B;

FIG. 7I is a schematic representation of a three-tier softwarearchitecture that can run upon the computing and memory architectureplatform of FIG. 7H, so as to implement the functionalities of theomni-directional image capturing and processing based bar code symbolreading system described FIG. 7B;

FIG. 8A is a perspective view of a fifth illustrative embodiment of theomni-directional image capturing and processing based bar code symbolreading system of the present invention installed in the countertopsurface of a retail POS station, shown comprising both vertical andhorizontal housing sections with coplanar illumination and imagingstations for aggressively supporting both “pass-through” as well as“presentation” modes of bar code image capture;

FIG. 8B is perspective view of the sixth embodiment of theomni-directional image capturing and processing based bar code symbolreading system of the present invention shown removed from its POSenvironment in FIG. 8A, and comprising a horizontal section assubstantially shown in FIGS. 5, 6A, A′. 7A′ or 7B for projecting a firstcomplex of coplanar illumination and imaging planes from its horizontalimaging window, and a vertical section that one horizontally-extendingand two vertically-extending spaced-apart coplanar illumination andimaging planes from its vertical imaging window, into the 3D imagingvolume of the system;

FIG. 8C is a block schematic representation of the omni-directionalimage capturing and processing based bar code symbol reading system ofFIG. 8B, wherein the complex of coplanar laser illuminating and linearimaging stations, constructed using either VLD or LED based illuminationarrays and linear (CMOS-based) image sensing arrays as shown in FIG. 6A,support automatic image formation and capture along each coplanarillumination and imaging plane therewithin, as well as automaticimaging-processing based object motion/velocity detection andintelligent automatic laser illumination control within the 3D imagingvolume of the system;

FIG. 8D is a block schematic representation of one of the coplanarillumination and imaging stations that can be employed in the system ofFIG. 8C, showing its planar light illumination array (PLIA), its linearimage formation and detection subsystem, its image capturing andbuffering subsystem, its imaging-based object motion and velocitydetection subsystem, and its local control subsystem (i.e.microcontroller);

FIG. 8E is a block schematic representation of the imaging-based objectmotion/velocity detection subsystem employed at each coplanarillumination and imaging station supported by the system, showncomprising an area-type image acquisition subsystem and an embeddeddigital signal processing (DSP) chip to support high-speed digital imagecapture and (local) processing operations required for real-time objectmotion and velocity detection;

FIG. 8F1 is a state transition diagram for the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIG. 8B, running the system control program described in FIGS. 6G1Aand 6G1B;

FIG. 8F2 is a state transition diagram for the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIG. 8B, running the system control program described in FIGS. 6G2Aand 6G2B;

FIG. 8F3 is a state transition diagram for the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIG. 8B, running the system control program generally described inFIGS. 6G3A and 6G3B;

FIG. 8G is a schematic diagram describing an exemplary embodiment of acomputing and memory architecture platform for implementing theomni-directional image capturing and processing based bar code symbolreading system described FIG. 8B;

FIG. 8H is a schematic representation of a three-tier softwarearchitecture that can run upon the computing and memory architectureplatform of FIG. 8H, so as to implement the functionalities of theomni-directional image capturing and processing based bar code symbolreading system described FIG. 8B;

FIG. 9A is a perspective view of a seventh illustrative embodiment ofthe omni-directional image capturing and processing based bar codesymbol reading system of the present invention installed in thecountertop surface of a retail POS station, shown comprising bothvertical and horizontal housing sections with coplanar illumination andimaging stations for aggressively supporting both “pass-through” as wellas “presentation” modes of bar code image capture;

FIG. 9B is perspective view of the seventh embodiment of theomni-directional image capturing and processing based bar code symbolreading system of the present invention shown removed from its POSenvironment in FIG. 9A, and comprising a horizontal section assubstantially shown in FIG. 2 for projecting a first complex of coplanarillumination and imaging planes from its horizontal imaging window, anda vertical section that projects three vertically-extending coplanarillumination and imaging planes into the 3D imaging volume of thesystem;

FIG. 9C is a block schematic representation of the omni-directionalimage capturing and processing based bar code symbol reading system ofFIG. 9B, wherein the complex of coplanar laser illuminating and linearimaging stations, constructed using either VLD or LED based illuminationarrays and linear (CMOS-based) image sensing array as shown in FIGS. 6Aand 6A′, support automatic image formation and capture along eachcoplanar illumination and imaging plane within the 3D imaging volume ofthe system, as well as automatic imaging-processing based object motionand velocity detection and intelligent automatic laser illuminationcontrol therewithin;

FIG. 9D is a block schematic representation of one of the coplanarillumination and imaging stations employed in the system embodiment ofFIGS. 9B and 9C, showing its planar illumination array (PLIA), itslinear image formation and detection subsystem, its image capturing andbuffering subsystem, its high-speed imaging-based object motion andvelocity sensing subsystem, and its local control subsystem;

FIG. 9E is a block schematic representation of the high-speedimaging-based object motion/velocity detection subsystem employed ateach coplanar illumination and imaging station supported by the systemof FIGS. 9B and 9C, shown comprising an area-type image acquisitionsubsystem and an embedded digital signal processing (DSP) chip tosupport high-speed digital image capture and (local) processingoperations required for real-time object presence, motion and velocitydetection;

FIG. 9F1 is a state transition diagram for the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIG. 9B, running the system control program generally described inFIGS. 6G1A and 6G1B;

FIG. 9F2 is a state transition diagram for the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIG. 9B, running the system control program generally described inFIGS. 6G2A and 6G2B;

FIG. 9F3 is a state transition diagram for the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIG. 9B, running the system control program generally described inFIGS. 6G3A and 6G3B;

FIG. 9G is a schematic diagram describing an exemplary embodiment of acomputing and memory architecture platform for implementing theomni-directional image capturing and processing based bar code symbolreading system shown FIG. 9B; and

FIG. 9H is a schematic representation of a three-tier softwarearchitecture that can run upon the computing and memory architectureplatform of FIG. 9G, so as to implement the functionalities of theomni-directional image capturing and processing based bar code symbolreading system shown FIG. 9B.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS OF THE PRESENTINVENTION

Referring to the figures in the accompanying Drawings, the variousillustrative embodiments of the illumination and imaging apparatus andmethodologies of the present invention will be described in greatdetail, wherein like elements will be indicated using like referencenumerals.

Overview of Coplanar Illumination and Imaging System and Methodologiesof the Present Invention

In the illustrative embodiments, the illumination and imaging apparatusof the present invention is realized in the form of an advanced,omni-directional image capturing and processing based bar code symbolreading system 10 that can be deployed in various applicationenvironments, including but not limited to retail point of sale (POS)stations 1, as shown in FIGS. 1 through 5F. As will be described ingreater detail below, in some embodiments of the present invention, thesystem will include only a horizontally-mounted housing, as shown inFigs. FIGS. 1 through 6H; in other embodiments, the system will includeonly a vertically-mounted housing; and yet in other embodiments, thesystem of the present invention will include both horizontal andvertically mounted housing sections, connected together in an L-shapedmanner, as shown in FIGS. 8A through 14I. All such embodiments of thepresent invention, the system will include at least one imaging window13, from which a complex of coplanar illumination and imaging planes 14(shown in FIGS. 3G through 3H) are automatically generated from acomplex of coplanar illumination and imaging stations 15A through 15Fmounted beneath the imaging window of the system, and projected within a3D imaging volume 16 defined relative to the imaging window 17.

As shown in FIG. 2, the system 10 includes a system housing having anoptically transparent (glass) imaging window 13, preferably, covered byan imaging window protection plate 17 which is provided with a patternof apertures 18. These apertures permit the projection of a plurality ofcoplanar illumination and imaging planes from the complex of coplanarillumination and imaging stations 15A through 15F. In the illustrativeembodiments disclosed herein, the system housing has a below counterdepth not to exceed 3.5″ (89 mm) so as to fit within demanding POScountertop environments.

The primary function of each coplanar illumination and imaging stationin the system, indicated by reference numeral 15 and variants thereof inthe figure drawings, is to capture digital linear (1D) or narrow-areaimages along the field of view (FOV) of its coplanar illumination andimaging planes using laser or LED-based illumination, depending on thesystem design. These captured digital images are then buffered anddecode-processed using linear (1D) type image capturing and processingbased bar code reading algorithms, or can be assembled together toreconstruct 2D images for decode-processing using 1D/2D image processingbased bar code reading techniques, as taught in Applicants' U.S. Pat.No. 7,028,899 B2, incorporated herein by reference.

In general, the omni-directional image capturing and processing systemof the present invention 10 comprises a complex of coplanar and/orcoextensive illuminating and imaging stations, constructed using (i)VLD-based and/or LED-based illumination arrays and linear and/area typeimage sensing arrays, and (ii) real-time object motion/velocitydetection technology embedded within the system architecture so as toenable: (1) intelligent automatic illumination control within the 3Dimaging volume of the system; (2) automatic image formation and capturealong each coplanar illumination and imaging plane therewithin; and (3)advanced automatic image processing operations supporting diverse kindsof value-added information based services delivered in diverse end-userenvironments, including retail POS environments as well as industrialenvironments.

As shown in the system diagram of FIG. 5A, the omni-directional imagecapturing and processing system of the present invention 10 generallycomprises: a complex of coplanar illuminating and linear imagingstations 15, constructed using the illumination arrays and linear imagesensing array technology; an multi-processor multi-channel imageprocessing subsystem 20 for supporting automatic image processing basedbar code symbol reading and optical character recognition (OCR) alongeach coplanar illumination and imaging plane, and corresponding datachannel within the system; a software-based object recognition subsystem21, for use in cooperation with the image processing subsystem 20, andautomatically recognizing objects (such as vegetables and fruit) at theretail POS while being imaged by the system; an electronic weight scalemodule 22 employing one or more load cells 23 positioned centrally belowthe system's structurally rigid platform 24, for bearing and measuringsubstantially all of the weight of objects positioned on the window 13or window protection plate 17, and generating electronic datarepresentative of measured weight of such objects; an input/outputsubsystem 25 for interfacing with the image processing subsystem 20, theelectronic weight scale 22, RFID reader 26, credit-card reader 27 andElectronic Article Surveillance (EAS) Subsystem 28 (including aSensormatic® EAS tag deactivation block 29 integrated in system housing30, and a Checkpoint® EAS antenna installed within the retail or workenvironment); a wide-area wireless interface (WIFI) 31 including RFtransceiver and antenna 31A for connecting to the TCP/IP layer of theInternet as well as one or more image storing and processing RDBMSservers 33 (which can receive images lifted by system for remoteprocessing by the image storing and processing servers 33); a BlueTooth®RF 2-way communication interface 35 including RF transceivers andantennas 35A for connecting to Blue-tooth® enabled hand-held scanners,imagers, PDAs, portable computers and the like 36, for control,management, application and diagnostic purposes; and a global controlsubsystem 37 for controlling (i.e. orchestrating and managing) theoperation of the coplanar illumination and imaging stations (i.e.subsystems) 15, electronic weight scale 22, and other subsystems. Asshown, each illumination and imaging subsystem 15A through 15F transmitsframes of digital image data to the image processing subsystem 20, forstate-dependent image processing and the results of the image processingoperations are transmitted to the host system via the input/outputsubsystem 25.

As shown in FIG. 5B, the coplanar or coextensive illumination andimaging subsystem (i.e. station 15), employed in the system of FIG. 5A,comprises: an image formation and detection subsystem 41 having a linearor area type of image sensing array 41 and optics 42 providing a fieldof view (FOV) 43 on the image sensing array; an illumination subsystem44 having one or more LED and/or VLD based illumination arrays 45 forproducing a field of illumination 46 that is substantially coplanar orcoextensive with the FOV 43 of the image sensing array 41; an imagecapturing and buffering subsystem 48 for capturing and buffering imagesfrom the image sensing array 41; an automatic object motion/velocitydetection subsystem 49, either locally or globally deployed with respectto the local control subsystem of the station, for (i) automaticallydetecting the motion and/or velocity of objects moving through at leasta portion of the FOV of the image sensing array 41, and (ii) producingmotion and/or velocity data representative of the measured motion andvelocity of the object; and a local control subsystem 50 for controllingthe operations of the subsystems within the illumination and imagingstations.

In the illustrative embodiments of the present invention disclosedherein and to be described in greater detail hereinbelow, each coplanarillumination and imaging station 15 has an (i) Object Motion andVelocity Detection Mode (State) of operation which supports real-timeautomatic object motion and velocity detection, and also (ii) a Bar CodeReading Mode (State) of operation which supports real-time automaticimage capturing and processing based bar code symbol reading. In someillustrative embodiments of the present invention, the ObjectMotion/Velocity Detection State of operation is supported at therespective coplanar illumination and imaging stations using its localcontrol subsystem and locally provided DSP-based image and/or signalprocessors (i.e. subsystem 49) to compute object motion and velocitydata which is used to produce control data for controlling the linearand/area image sensing arrays employed at the image formation anddetection subsystems.

Forming and Detecting High-Contrast Digital Images of Objects at POSEnvironments Using a Mixture of Visible and Invisible IlluminationAccording the Principles of the Present Invention

In order to eliminate or otherwise reduce the obnoxious effects thathigh levels of visible illumination (i.e. brightness, glare etc.) causemost humans at retail pos environments, it is an object of the presentinvention to use a mixture of visible and invisible illumination to formand detect high-contrast digital images of objects at POS environments,with little sacrifice on the image quality under specific situations.The possible embodiments of this illumination control method include,but are not limited to, fixed ratio spectrum mixture, and adaptivespectrum component control scheme.

General Types of Illumination System Designs Employing Methods ofControlling the Ratio of Visible/Invisible Spectral Energy in theIllumination Beam for Reducing Brightness to Human Operators/Viewers andProviding Sufficient Image Contrast in Captured Digital Images ofObjects at the POS Environment

In principle, there are two general methods of managing the ratio ofvisible/invisible spectral energy in the illumination beam during objectillumination and imaging operations; (1) statically controlling theratio of visible/invisible spectral energy in the illumination beamduring object illumination and imaging operations; and (2)adaptively/dynamically controlling the ratio of visible/invisiblespectral energy in the illumination beam during object illumination andimaging operations. These two approaches will be described in greattechnical detail below.

Method of Statically Controlling the Ratio of Visible/Invisible SpectralEnergy in the Illumination Beam During Object Illumination and ImagingOperations

According to this first method, the ratio of visible to invisible (IR)spectral energy/power in the (planar, narrow-area or wide-area)illumination beam is maintained substantially static or fixed bycontrolling the current supplied to the visible laser and infrared laserdiodes during object illumination and imaging operations. The static orfixed mixture ratio can be realized by setting one or several differentpreset values of current supplied to drive the Visible Laser Diodes(VLDs) and Infrared Laser Diodes (IRLDs), or visible LEDs and IR LEDs,or a combination thereof, in the Illumination Subsystem, as shown inFIG. 5C. Through experimentation, the visible/invisible photonic energymixture ratio [i.e. VIS/IR] can be optimized under different operatingsituations, in effort to (i) satisfy the reduction of visual brightnessat the POS station to ensure humans are not disturbed by theillumination field, as well as (ii) achieve sufficient image contrast incaptured digital images to ensure satisfactory image processing.

Method of Adaptively/Dynamically Controlling the Ratio ofVisible/Invisible Spectral Energy in the Illumination Beam During ObjectIllumination and Imaging Operations

According to the second method, the ratio of visible to invisible (IR)spectral energy/power in the (planar, narrow-area or wide-area)illumination beam is dynamically maintained/managed by adaptivelycontrolling the electrical current supplied to the visible and infrareddiodes during object illumination and imaging operations. The ratiobetween visible and infrared wavelength components can be controlled bysupplying different driving currents to the visible and invisible diodes(e.g. VLDs and IRLDs or visible LEDs and IR LEDs), as required tominimize visual brightness (to humans) at the POS station during objectillumination and imaging operations, while achieving sufficient imagecontrast quality to ensure satisfactory image processing. The diodedrive currents can be controlled by the following process: (i) drivingthe diodes with a predetermined/default values of drive currents toilluminate the object with a spectral mixture of illumination; (ii)capturing one or more digital images of the illuminated object andmeasuring (in real-time) image contrast quality (e.g. within the digitalimage processing subsystem or other programmed imaged processor) so asto generate feedback or control data; and (iii) using this feedback orcontrol data to dynamically generate the necessary values for theadjusted diode current control signals that are used to drive the diodesand produce an optimal mixture of illumination during objectillumination and imaging operations. This control process is illustratedin FIGS. E2, F2 and G2 for various illustrative embodiments of thepresent invention.

A Coplanar Laser Illumination and Imaging Subsystem Producing PlanarIllumination Beam Having a Fixed Ratio of Visible and IR Spectral Energy

FIG. 5C shows illustrative embodiment of a coplanar laser illuminationand imaging subsystem (i.e. station) that can be deployed in any digitalimage capturing and processing system of the present invention disclosedand/or taught herein. As shown, this subsystem (i.e. station) comprises:(a) an image formation and detection (IFD) subsystem having (i) an imagesensing array and (ii) optics providing a field of view (FOV) on theimage sensing array; (b) an spectral-mixing based illumination subsystemproducing a first field of visible illumination (produced from an arrayof VLDs) and a second field of invisible illumination (produced from anarray of IR LDs) that spatially overlap and spatially/temporallyintermix with each other while having a preset relative power ratio(VIS/IR), and are substantially coplanar or coextensive with the FOV ofthe image sensing array; (c) an integrated laser beam despecklingmechanism associated with the IFD subsystem (as disclosed in WIPOPublication No. WO/2002/043195 or in the present Specification; (d) animage capturing and buffering subsystem for capturing and bufferingimages from the image sensing array; (e) an automatic objectmotion/velocity detection subsystem for automatically detecting themotion and velocity of an object moving through at least a portion ofthe FOV of the image sensing array; and (f) a local control subsystemfor controlling the operations of the subsystems within the illuminationand imaging station.

A Coplanar Laser Illumination And Imaging Subsystem Producing PlanarIllumination Beam Having a Fixed Ratio of Visible and IR SpectralEnergy, and Employing Integrated HFM/OMUX Despeckling Techniques forSpeckle Pattern Noise Reduction

FIG. 5D shows another embodiment of a coplanar laser illumination andimaging subsystem (i.e. station) that can be deployed in any digitalimage capturing and processing system of the present invention disclosedand/or taught herein. As shown, the subsystem (i.e. station) comprises:(a) an image formation and detection (IFD) subsystem having (i) an imagesensing array and (ii) optics providing a field of view (FOV) on theimage sensing array; (b) an spectral-mixing based illumination subsystemproducing a first field of visible illumination (produced from an arrayof VLDs) and a second field of invisible illumination (produced from anarray of IR LDs) that spatially overlap and spatially/temporallyintermix with each other while having a preset relative power ratio(VIS/IR), and are substantially coplanar or coextensive with the FOV ofthe image sensing array; (c) an integrated HFM-OMUX laser despecklingmechanism associated with the IFD subsystem and employing thehigh-frequency modulation HFM techniques of the present inventiondisclosed in FIGS. 5H through 5N, and optical multiplexing (OMUX)techniques of the present invention disclosed in FIGS. 5O through 5X7;(d) an image capturing and buffering subsystem for capturing andbuffering images from the image sensing array; (e) an automatic objectmotion/velocity detection subsystem for automatically detecting themotion and velocity of an object moving through at least a portion ofthe FOV of the image sensing array; and (f) a local control subsystemfor controlling the operations of the subsystems within the illuminationand imaging station.

A Coplanar Laser Illumination and Imaging Subsystem (I.E. Station)Producing Planar Illumination Beam Having a Fixed Ratio of Visible andIR Spectral Energy, and Employing Alternative Despeckling Techniques forSpeckle Pattern Noise Reduction

FIG. 5E1 shows another illustrative embodiment of a coplanar laserillumination and imaging subsystem (i.e. station) that can be deployedin any digital image capturing and processing system of the presentinvention disclosed and/or taught herein. As shown, the subsystemcomprises: (a) an image formation and detection (IFD) subsystem having(i) an image sensing array and (ii) optics providing a field of view(FOV) on the image sensing array; (b) an spectral-mixing basedillumination subsystem producing a first field of visible illumination(produced from an array of VLDs) and a second field of invisibleillumination (produced from an array of IR LDs) that spatially overlapand spatially/temporally intermix with each other while having aadaptively/dynamically set relative power ratio (VIS/IR), and aresubstantially, coplanar or coextensive with the FOV of the image sensingarray; (c) an generalized integrated laser de-speckling mechanismassociated with the IFD subsystem (as disclosed in WIPO Publication No.WO/2002/043195 or in the present Specification); (d) an image capturingand buffering subsystem for capturing and buffering images from theimage sensing array; (e) an automatic object motion/velocity detectionsubsystem for automatically detecting the motion and velocity of anobject moving through at least a portion of the FOV of the image sensingarray; and (f) a local control subsystem for controlling the operationsof the subsystems within the illumination and imaging station.

The flow chart of FIG. 5E2 describes the primary steps involved in themethod of adaptively controlling the spectral composition of the planarillumination beam produced from the illumination subsystem of thecoplanar laser illumination and imaging subsystem (i.e. station)illustrated in FIG. 5E1.

Coplanar Laser Illumination and Imaging Subsystem of the PresentInvention Producing a Substantially Planar Illumination Beam (PLIB)Having a Dynamically/Adaptively Controlled Ratio of Visible and IRSpectral Energy, and Employing Integrated HFM/OMUX DespecklingTechniques for Speckle Pattern Noise Reduction

FIG. 5F1 shows another embodiment of a coplanar laser illumination andimaging subsystem (i.e. station) that can be deployed in any digitalimage capturing and processing system of the present invention disclosedand/or taught herein. As shown, the subsystem comprises: (a) an imageformation and detection (IFD) subsystem having (i) an image sensingarray and (ii) optics providing a field of view (FOV) on the imagesensing array; (b) an spectral-mixing based illumination subsystemproducing a first field of visible illumination (produced from an arrayof VLDs) and a second field of invisible illumination (produced from anarray of IR LDs) that spatially overlap and spatially/temporallyintermix with each other while having a dynamically set relative powerratio (VIS/IR), and are substantially coplanar or coextensive with theFOV of the image sensing array; (c) an integrated HFM-OMUX based laserde-speckling mechanism associated the IFD subsystem (employing thehigh-frequency modulation HFM techniques of the present inventiondisclosed in FIGS. 5H through 5N and optical multiplexing (OMUX)techniques of the present invention disclosed in FIGS. 5O through 5X7);(d) an image capturing and buffering subsystem for capturing andbuffering images from the image sensing array; (e) an automatic objectmotion/velocity detection subsystem for automatically detecting themotion and velocity of an object moving through at least a portion ofthe FOV of the image sensing array; and (f) a local control subsystemfor controlling the operations of the subsystems within the illuminationand imaging station.

The flow chart in FIG. 5F2 describes the primary steps involved in themethod of adaptively controlling the spectral composition of the planarillumination beam produced from the illumination subsystem of thecoplanar laser illumination and imaging subsystem (i.e. station)illustrated in FIG. 5F1.

Coextensive Area-Type Illumination and Imaging Subsystem of the PresentInvention Producing Area-Type Illumination Beam Having anAdaptively/Dynamically Controlled Ratio of Visible and IR SpectralEnergy Generated by LED-Based Illumination Sources

FIG. 5G1 shows an illustrative embodiment of a coextensive area-typeillumination and imaging subsystem (i.e. station) that can be deployedin any digital image capturing and processing system of the presentinvention disclosed and/or taught herein. As shown, the subsystemcomprises: (a) an image formation and detection (IFD) subsystem having(i) an image sensing array and (ii) optics providing a field of view(FOV) on the image sensing array; (b) an spectral-mixing basedillumination subsystem producing a first field of visible illumination(produced from an array of visible LEDs), and a second field ofinvisible illumination (produced from an array of IR LEDs) thatspatially overlap and spatially/temporally intermix with each otherwhile having an adaptively/dynamically set relative power ratio(VIS/IR), and are substantially coextensive with the FOV of the imagesensing array; (c) an image capturing and buffering subsystem forcapturing and buffering images from the image sensing array; (d) anautomatic object motion/velocity detection subsystem for automaticallydetecting the motion and velocity of an object moving through at least aportion of the FOV of the image sensing array; and (f) a local controlsubsystem for controlling the operations of the subsystems within theillumination and imaging station.

The flow chart of FIG. 5G2 describes the steps involved in the method ofadaptively/dynamically controlling the spectral composition of thearea-type illumination beam produced from the illumination subsystem ofthe coextensive area-type illumination and imaging subsystem (i.e.station) illustrated in FIG. 5G1.

Detailed Description of Coplanar Laser Illumination and ImagingSubsystem of the Present Invention Producing a Composite SubstantiallyPlanar Illumination Beam (PLIB) from PLIMs Having aDynamically/Adaptively Controlled Ratio of Visible and IR SpectralEnergy and Employing an Integrated HFM/OMUX Despeckling Mechanism of thePresent Invention for Speckle Pattern Noise Reduction

FIG. 5H shows an illustrative embodiment of a coplanar laserillumination and imaging subsystem of the present invention producing acomposite substantially planar illumination beam (PLIB) from PLIMshaving a dynamically/adaptively controlled ratio of visible and IRspectral energy, and employing an integrated HFM/OMUX despecklingmechanism of the present invention for speckle pattern noise reduction.As shown, the system comprises: (a) a planar laser illumination array(PLIA) subsystem including (i) a first linear array of threedynamically/adaptively driven VLD-Based planar laser illuminationmodules (PLIMs), and (ii) a second planar laser illumination array(PLIA) having three dynamically/adaptively driven IRVD-Based PLIMs, eachoperated under the control of a local control subsystem, in response tocontrol data produced by the image processing subsystem running thespectral-mixture control algorithm of the present invention (FIGS. 5E2,5F2 and 5G2); (b) an image formation and detection (IFD) subsystemhaving a linear (1D) or area-type (2D) digital image detection array(having a narrow-area field of pixels actively driven), and (ii) opticsfor forming a field of view on the linear image detection array (or thenarrow-area field of pixels on a 2D image detection array); (c) an imagecapture and buffering subsystem for capturing and buffering digitalimages formed and detected by the IPD subsystem; (d) a local controlsubsystem (e.g. programmed microprocessor performing local controlfunctions within the station including the generation of control dataand signals for driving each of the PLIMs in each PLIA; and (e) adigital image processing subsystem (which may be provided for global usewithin the system in which the subsystem is integrated, or local use asthe case may be) for processing digital images captured and buffered bythe subsystem, and carrying out the spectral-mixture control algorithmof the present invention described in FIGS. 5E2, 5F2 and 5G2.

In FIG. 5I1, each PLIM employed in the Illumination Subsystem depictedin FIG. 5H, is shown comprising: a VLD; current drive circuitry; HFMcircuitry; a OMUX module; and cylindrical illumination lens array. Whenthe HFM control signal from the local system control subsystem is HRMOFF, the HFM circuit is disabled and there is no high frequencymodulation of the drive current supplied to the VLD. Consequently, asshown in FIG. 5J1, the drive current supplied to the VLD produces onlysingle narrow-band peak about the characteristic wavelength of the VLD.However, as shown in FIGS. 5I2 and 5J2, when the local control subsystemproduces an HFM ON signal, the HFM circuitry is enabled and supplies ahigh frequency modulated diode drive current to the VLD causing the VLDto produce a spectral sideband components about the centralcharacteristic wavelength of the VLD, thereby reducing the coherence ofthe laser illumination beam as well as its coherence length, driving theOMUX module of the PLIM. This coherence-reduced laser beam, with itsreduced coherence length characteristics, is perfectly suited fordriving any of the laser beam despeckling mechanism disclosed in WIPOPublication No. WO 2002/043195 or in the present Specification.

High-Frequency Modulation (HFM) Based Illumination Module of PresentInvention Realized on a Flexible Circuit for Use in Digital ImagingSystems

FIG. 5K1 shows a first illustrative embodiment of a singleHFM-OMUX-Based PLIM of the present invention which can be employed inthe HFM-OMUX based illumination subsystem of FIG. 5H, as well as innumerous other diverse applications in industry (e.g. digital imaging,projection television, photolithographic illumination and imaging, etc),As shown, the HFM-OMUX-Based PLIM comprises: a flexible circuit as shownin FIGS. 5N1 and 5N2, and supporting (i) a VLD or IR laser diode (IRLD)and (ii) a HFM circuitry mounted in close proximity to the VLD or IRLD.As illustrated, the flexible circuit is connected to amicroprocessor-controlled current driver circuitry realized on a PCboard, and controlled by the local control subsystem which generatesmicroprocessor controlled signals. FIG. 5L shows a schematic diagram ofthe HFM circuitry of the illustrative embodiment employed in each PLIMof the HFM-OMUX Based Illumination Subsystem of FIG. 5H. FIG. 5Mprovides a schematic diagram of the current driver circuitry of thepresent invention, employed in each PLIM of the HFM-Based IlluminationSubsystem of FIG. 5H. In the illustrative embodiments, the HFM circuitrycan be realized using the Toshiba TC9384FUG High Frequency Oscillator ICfor Laser Diode, or SANYO's SMA4205 High Frequency Oscillator IC forLaser Diode. In the illustrative embodiments, where the SANYO red laserdiode DL-3147-060 (having a characteristic wavelength of about 650nanometers and low threshold current of about 20 milliamperes) is usedto realize the VLDs, the preferred frequency of oscillation is 450 MHZ.However, it is expected that other higher values can be used to provideexpectedly good performance results. As shown in FIGS. 5N1 and 5N2, theflexible circuit used in the first illustrative embodiment, supports thelaser diode and HFM circuitry at its distal end, and connects to the PCboard, supporting the diode current drive circuitry, on its proximalend.

FIG. 5K2 shows a second illustrative embodiment of a singleHFM-OMUX-Based PLIM of the present invention which can be employed inthe HFM-OMUX based illumination subsystem of FIG. 5H, as well as innumerous other diverse applications in industry (e.g. digital imaging,projection television, photolithographic illumination and imaging, etc).As shown, the HFM-OMUX-Based PLIM comprises: a flexible circuit as shownin FIGS. 5N1 and 5N2, and supporting (i) a VLD or IR laser diode (IRLD),(ii) a HFM circuitry mounted in close proximity to the VLD or IRLD, and(iii) a microprocessor-controlled current driver circuitry which isconnected to the HFM circuitry and interfaced with the local controlsubsystem. The primary difference between the first and secondillustrative embodiments shown in FIGS. 5K1 and 5K2 is that in thesecond illustrative embodiment, the diode current drive circuitry aswell as the HFM circuitry and the laser diode (e.g. VLD, IRVD, visibleLED or IR LED) are mounted on the distal portion of the flexiblecircuit, as shown in FIGS. 5N3 and 5N4.

Principles of Operation of the Optical Beam Multiplexing (OMUX) Methodof the Present Invention

A primary principle of operation of the optical multiplexing (OMUX)mechanism or module of the invention is duplicating (or multiplicating)the incoherence conditions/requirements that are provided by multipleradiation sources, but only by using radiation emanating from a singleradiation source (e.g. VLD or IRLD). According to the principles of thepresent invention, such incoherence requirements can be duplicated bysplitting or (otherwise dividing) a laser beam into two or more laserbeams, creating a phase delay (temporal delay) between those multiplelaser beams, and physically (spatially) separating them from one anotherso that each laser beam traverses a different pathlength. The effect ofsuch optical beam multiplexing is to create additional virtual radiationsources that behave the same as independent real radiation sources wouldbehave. However, a primary advantage of this OMUX method of the presentinvention is that the resulting virtual radiation sources occupy orrequire less physical space than real sources, thereby allowing theresulting digital image capture and processing system (e.g. bar codereader) to be constructed in a highly compact fashion. Another advantageof the OMUX method of the present is that its practice involves nomoving parts, thereby improving the ease of alignment and reliabilityand avoiding limitations on scanning speed.

First Illustrative Embodiment of the Optical Despeckling Device of thePresent Invention

FIG. 5O shows a first illustrative embodiment of the optical laser beamdespeckling device of the present invention, based on optical beammultiplexing (e.g. duplicating or multiplicating) principles describedabove and deployable in each PLIM of the HFM-based illuminationsubsystem of FIG. 5P. The primary purpose of this OMUX-based despecklingmechanism is to reduce (i) the coherence of the resultingplanar/narrow-area illumination beam generated therefrom, and (ii) thusthe amount of speckle pattern noise observed at the image detectionarray of the image formation and detection (IFD) subsystem in thedigital image capturing and processing system in which subsystems arecontained.

As shown in FIG. 5O, the simple OMUX-based laser beam despeckling moduleor mechanism comprises: an optical window structure (e.g. glass plate)having parallel polished sides with a partial mirror coating on oneside, and a partial beam-splitter coating on the other side. As shown,the partial beam-splitter coatings are aligned such that one laser beamcomes in on the one side of the glass plate, whereas multiplephase-delayed laser beams exit the other side of the optical structure.The beam splitter coating is tuned to a specific efficiency such as toequalize the first and last beam intensities and thereby maximize thelaser beam despeckling effect. In the illustrative example, three laserbeams leave the exit side, and the beam splitter coating is tuned toabout 64% reflectivity. The result is an optical element having a 91%overall efficiency, and a despeckling effect equivalent to 2.87 sources.The maximum possible effect would be 3.0 sources, so therefore, itshould be noted that this design is a very efficient and effectivedespeckling solution.

During operation, the focused beam will enter the optical multiplexor(OMUX) element, through a high-transmission optical surface, i.e. withno coating or an AR coating. The laser beam then travels through theoptical material losing an insignificant amount of energy (i.e.experiences low absorption) and then arrives at a beam splittingcoating. Some of the laser beam energy will be transmit therethrough,leaving the optical multiplexor device, and some laser beam energy willremain inside the multiplexor device, reflecting off of the beamsplitter coating. The internal beam will pass back through the opticalmaterial and arrive at a high-reflector, where nearly all of the laserbeam energy will be redirected towards the beam splitter. This cyclecontinues until the internal laser beam finally encounters ahigh-transmission surface where all the remaining beam energy leaves theoptical multiplexor. In the preferred embodiment, three laser beams exitthe multiplexor (OMUX) device. A cylindrical-type illumination lensarray, disposed beyond but in proximity with the OMUX device will thenintercept the exiting laser beams and spread their radiant energy sothat the three expanded laser beams now overlap to produce a compositesubstantially planar illumination beam (PLIB) suitable for use in alinear illumination system, linear illumination and imaging system, orother applications where laser speckle noise is to be substantiallyreduced or eliminated. In the case of a PLIIM-based bar code reader, theplanar illumination beam will then reflect off of a barcode symbol andbe collected by a lens system for focusing onto a digital image sensor.

In alternate embodiments of the HFM-OMUX based PLIA of the presentinvention, a single beam may be split up into more than just threebeams, as shown in FIG. 5V. As the number of beams increases, thereflectivity of the beam splitter coating must be increased to maintainthe most effective despeckling by making the power in the first and lastbeams approximately equal. Alternately, a more complex optical systemcould be designed and constructed so that the reflectivity of the beamsplitter coating varies along the surface such that all of theindividual laser beams have equal power, thus truly maximizing thedespeckling effect. Alternatively, the beam splitter coating can bebroken up discretely into as many pieces as desired. For example, tenbeams produced with two coatings may result in the most cost-effectivesolution.

First Illustrative Embodiment of the Planar Laser Illumination Array(PLIA) of the Present Invention Employing HFM-OMUX Based PLIMs

As shown in FIG. 5P, a HFM-OMUX based planar laser illumination array(PLIA) device can be constructed by arranging together multiple (e.g.three or more) planar laser illumination modules (PLIMs) utilizing theHFM and OMUX principles of the present invention in combination witheach other, and perhaps other despeckling techniques (e,g. polarizationencoding). As shown, each PLIM comprises: (i) a laser source (e.g. VLD,IR LD, etc) driven preferably by the HFM-based diode current drivecircuitry, as shown in FIGS. 5I1 through 5N4 and described above; (ii) acollimating lens (i.e. optics) disposed beyond the laser source; (ii) alaser beam optical multiplexor (OMUX) device of the present inventiondisposed beyond the collimating lens; and (iv) preferably a singlecylindrical-type planarizing-type illumination lens array disposedbeyond the OMUX, and arranged as an integrated assembly. The result isto generate a plurality of substantially planar coherence-reduced laserillumination beams (PLIBs), from the PLIMs, that form a compositesubstantially planar laser illumination beam (PLIB) having substantiallyreduced spatial/temporal coherence. Such resulting laser beam propertiessubstantially reduces the amount of speckle pattern noise observed inimages of an illuminated object at the image detection array of theimage formation and detection (IFD) subsystem, by virtue oftime-averaging of multiple coherence-reduced speckle noise patterns,during the photo-integration time period of the digital image detectionarray of the image formation and detection (IFD) subsystem employedwithin the digital image capturing and processing system in whichsubsystems cooperate.

Coplanar Illumination and Imaging Subsystem Employing Dual HFM-OMUXBased PLIAs of the Present Invention

FIGS. 5Q through 5U show an exemplary implementation of the firstillustrative implementation of the coplanar illumination and imagingsubsystem depicted in FIGS. 5E1 and 5E2, employing a pair of PLIAsillustrated in FIGS. 5O and 5P, with an IFD subsystem and its imageforming optics disposed therebetween. As shown in FIG. 5U, the pair ofPLIA collectively support three VLDs and three IR VDs mounted in thePLIA support blocks, to which the flexible HFM circuits of the presentinvention are connected on one end, and to PC board on the other,thereby forming an electrical interface with the corresponding laserdiode current drive circuits realized thereon. Preferably, the VLDs andIRLDs are arranged in a spatially alternating manner, although otherspatial arrangements are possible and should work with good spectralmixing results.

Second Illustrative Embodiment of the Laser Beam Despeckling Device ofthe Present Invention

FIG. 5V shows a second illustrative embodiment of the laser beamdespeckling device of the present invention, shown constructed as anOMUX comprising: a single glass plate bearing reflective andsemi-reflective coatings as shown to optically multiplex an input laserbeam into multiple spatial-coherence reduced output laser beams, whichare then planarized into composite substantially planar laserillumination beam (PLIB) by a multi-cylinder planarizing-typeillumination lens array disposed in close proximity therewith.

Method of Reducing Laser-Based Speckle Pattern Noise at the ImageDetection Array of the IFD Subsystem Using the HFM Current Drive Methodin Combination with any Optical Despeckling Method of the PresentInvention

Laser-based speckle pattern noise can be reduced at the image detectionarray of the IFD subsystem using the HFM current drive method of thepresent invention in combination with any optical despeckling method ofthe present invention, including the optical beam multiplexor (OMUX)devices illustrated in FIGS. 5O and 5V, as well as the polarizationdespeckler devices illustrated in FIGS. 5W1 through 5W6, so as to form asingle, ultra-compact high-performance laser beam despeckler.

While optical multiplexing and/or polarization-encoding despecklingmethods disclosed herein contributes its own independent measure ofeffective despeckling, it is important to point out that Applicants havediscovered, to great surprise, that the broadening of the illuminationspectrum of the input laser beam, using the HFM-based diode currentdriving technique disclosed herein, causes the other despeckling methodsto work better, in particular the laser beam multiplexor (OMUX) device,apparently by virtue of accompanying reduction in coherence length ofthe laser, caused by spectral broadening caused by the use of HFM diodecurrent drive techniques. Since the different methods are independent,there effects are multiplicative, resulting in a very large total effectin speckle pattern noise power reduction through time-averagingprinciples (e.g. during the photo-integration period of the imagedetection array, in the case of digital imaging systems, or during thephoto-integration time period of the retinal surface of the eye of ahuman observer, in the case where the despeckled laser beam is used toproject images on a display screen in projection television systems andthe like).

The effectiveness of any despeckler can be measured in terms of thenumber of effective independent sources to which its behavior iscomparable. With the combination despeckler, as shown in FIGS. 5Hthrough 5V, it is possible to achieve speckle noise reduction effectsthat are equivalent to using twelve (12) or more spatially and/ortemporally incoherent laser radiation sources (for illuminationpurposes) in a space not much larger than what a single source occupies.Also, an even greater effect can be achieved with small increases insize of the device. A clear advantage of the combination-baseddespeckling methods of the present invention is that its now possible torealize laser-illuminated digital imaging-based bar code reading systemsof ultra-compact construction, hitherto unachievable. Moreover, suchdesign objects can be achieved without the disadvantage of moving parts,thereby improving the ease of alignment and reliability and avoidinglimitations on scanning speed.

Third Illustrative Embodiment of the Laser Beam Despeckling Device ofthe Present Invention Based on Polarization-Encoding of MultiplexedLaser Beam Components

In FIG. 5W1, the third illustrative embodiment of the laser beamdespeckling device of the present invention is designed and constructedas a polarization-encoding OMUX device. As shown, the input laser beamis multiplexed into at least two components each of which is thenimparted with a different polarization state, so that upon recombinationin the output beam, at least two independent speckle patterns will begenerated at the image detection array, over its photo-integration timeperiod of the image detection array, and the total speckle pattern noisepower will have been reduced through time-averaging principles disclosedin great detail in Applicants' WIPO Patent Publication No.WO/2002/043195, incorporated herein by reference, Notably, thepolarization-encoding optical multiplexor (OMUX) of FIG. 5W1 reflectsthe simple case where the input laser beam (typically linearlypolarized, as is common in laser sources) is split in two laser beamcomponents, where one component of the split beams has its polarizationrotated 90 degrees, and thereafter, the laser beams are recombined, sothat the resulting illumination will generate two independent specklepatterns, spatially overlapping at the exit surface of the OMUX device,and wherein the total speckle pattern noise power will have been reducedby approximately 30% through time-averaging principles (e.g. during thephoto-integration period of the image detection array, in the case ofdigital imaging systems, or during the photo-integration time period ofthe retinal surface of the eye of a human observer, in the case wherethe despeckled laser beam is used to project images on a display screenin projection television systems and the like). The effect is equivalentto creating two virtual sources that behave the same as independent realsources.

One advantage of this polarization-encoding laser beam despecklingmethod of the present invention is that the number of sources iseffectively doubled with only a small additional space requirement ascompared to employing twice as many real laser sources, thus allowing alaser-illuminated digital-imaging bar code reader to be madesignificantly more compact. Another advantage with this method ofdespeckling is that it involves no moving parts, improving ease ofalignment and reliability and avoiding limitations on scanning speed.

As shown in FIG. 5W1, one method of efficiently splitting andrecombining the laser beam with orthogonal polarization states can beachieved using a laser beam despeckling device comprising: a three-sidedprism and a ½ wave retarder plate disposed between a pair of mirrorsarranged as shown, to optically multiplex an input laser beam into asingle temporal-coherence reduced output laser beam, for subsequentplanarization a multi-cylinder planarizing-type illumination lens arraydisposed in close proximity therewith. In this embodiment, two sides ofthe prism are coated with a 50% beam splitter coating whereas its thirdside is coated with a high reflective mirror. All the light enters theoptical subsystem from the left side and exits the subsystem from theright side, with the exception of internal scattering and absorptionlosses and small reflections off the ½ wave plate. A minor modificationto aid in the efficiency is to substitute a ¼ wave plate for the ½ waveplate and adhere it to one of the two mirrors such that the beam passesthrough it twice with each bounce off that mirror. In this configurationthe losses due to reflection off the wave plate will be reduced. Thefunctioning of this system is such the laser beam traverses multiplepaths to go from the entrance aperture to the exit, aperture andportions of the laser beam will cycle around inside the subsystem beforeexiting as an output beam. When all the paths are considered, it is seenthat roughly half the energy will exit the subsystem with the samepolarization state that entered it, while the other half will have apolarization state orthogonal to the initial state. Such polarizationstate differences the internally generated, and ultimately recombinedbeam components effectively reduced the temporal coherence among theseinternally generated and recombined beam components, and thus helpsreduced speckle pattern noise power during time-based integration at thedigital image detection array of the IFD subsystem.

Fourth Illustrative Embodiment of the Laser Beam Despeckling Device ofthe Present Invention Based on Polarization-Encoding of MultiplexedLaser Beam Components

FIG. 5W2 shows a fourth illustrative embodiment of the laser beamdespeckling device of the present invention, designed and constructed asa polarization-encoding OMUX device comprising: a polarization beamsplitter/reflector arranged on a diagonal surface of an optical cubeformed by a pair of prisms arranged together as a cubic structure; andorthogonally-arranged mirrors supported on the surfaces of the opticalcube; wherein each surface also each bears a ¼ wave retarder as shown,to optically multiplex an input laser beam into a singletemporal/spatial-coherence reduced output laser beam, for subsequentplanarization a multi-cylinder planarizing-type illumination lens arraydisposed in close proximity therewith. The device can be used in a PLIMhaving a VLD (or IRLD) and a collimating lens to focus the light beam itenters the side of the cube, and strikes the beam splitter with onelinear polarization state and exits with two orthogonal states, as shownin FIG. 5W2. The output laser beam is then transmitted through acylinder lens will then intercept the beam and spread the light into alinear or planarized illumination field. The substantially planar fieldof illumination will then reflect off of a barcode or other object to beimaged, and collected by a lens system for focusing onto a digital imagedetection array of the IFD subsystem.

During operation, linearly polarized light enters from the left side ofthe optical cube, with a polarization orientation of 45 degrees. Whenthe beam encounters the diagonal surface of the optical cube, half ofthe light beam is reflected downstream as S-polarized light, while theother half of the light beam is transmitted as P-polarized light. Bothbeams then reflect off a mirror, passing twice through a ¼ wave plate.This causes each of their polarizations to be rotated 90 degreesrelative to each other. Because of the change in polarization, the beamthat reflected off the diagonal at its first encounter now passesthrough it, and vice versa for the other beam. As a result, both beamsexit through the top surface producing a combination of orthogonalpolarization states.

Fifth Illustrative Embodiment of the Laser Beam Despeckling Device ofthe Present Invention Based on Polarization-Encoding of MultiplexedLaser Beam Components

FIG. 5W3 shows a fifth illustrative embodiment of the laser beamdespeckling device of the present invention, constructed as apolarization-encoding OMUX device comprising: four mirrors, with threeof which being arranged as three sides of a cubic structure, and thefourth mirror arranged parallel and offset from the third mirror, asshown; a ¼ wave retarder plate arranged in the corner of the cubicstructure formed by the first and second mirrors as shown; a beamsplitter arranged parallel and between the first and third mirrors, tooptically multiplex and polarization-encode an input laser beam into twotemporal/spatial-coherence reduced output laser beams with differentpolarization states, for subsequent planarization a multi-cylinderplanarizing-type illumination lens array disposed in close proximitytherewith. This polarization OMUX design essentially combines severaldespeckling methods to efficiently split the laser beam into twocomponents having orthogonal polarization states, and recombining thesecomponents so as to create a two spatially and temporally separatedlaser beams at the output of this optical subsystem. In this method, abeam splitter is used with a 50% reflective coating to equally separatethe beam into two parts. A ¼ wave plate is inserted in the one leg ofthe split beam to intercept that beam twice and rotate its polarizationby 90 degrees. Notably, a ½ wave plate could easily be used in one placeof the ¼ wave plate, After being redirected by mirrors, the two splitbeam components meet again at the beam splitter coming in from oppositesides. As a result, the two emerging beams are composed of half of onelinear polarization state and half of an orthogonal state.

Sixth Illustrative Embodiment of the Laser Beam Despeckling Device ofthe Present Invention Based on Polarization-Encoding of MultiplexedLaser Beam Components

In the sixth illustrative embodiment of the laser beam despecklingdevice of the present invention, each internally-generated (multiplexed)laser beam in the OMUX device of FIGS. 5O and 5V, is also imparted witha different polarization state, so that the resulting pair of outputlaser beams are encoded with different polarization states as well ashaving tranversed different optical paths, before being planarized intoa composite planar laser illumination beam (PLIB). Consequently, thespeckle pattern noise generated from such an output laser beam on thesurface of a digital image detection array (or on an image displaysurface) will have a substantially reduced speckle pattern noise level.FIG. 5W4 shows an embodiment of such a laser beam despeckling device,comprising: a ¼ wave retarder plate disposed between a pair of glassplates bearing mirror and beam-splitter coatings as shown, so as tooptically multiplex an input laser beam into two spatial and temporalcoherence reduced output laser beams. The output beam is thensubsequently planarized by a multi-cylinder planarizing-typeillumination lens array disposed in close proximity therewith. Thisdesign employs a second method of efficiently splitting and recombiningthe laser beam with orthogonal polarization states.

This design employs a second method of efficiently splitting andrecombining the laser beam with orthogonal polarization states. In thisembodiment, as the laser beams pass back and forth between the tworeflective layers/coatings, the polarization states of these laser beamcomponents become mixed, as shown by the fractions of lambda (awavelength) in the figure. This model would have a despecklingaffectivity equivalent to nine (9) real laser beam sources.

Seventh Illustrative Embodiment of the Laser Beam Despeckling Device ofthe Present Invention

FIG. 5W5 shows a seventh illustrative embodiment of the laser beamdespeckling device of the present invention, similar in many ways to thepolarization-encoding OMUX device of FIG. 5W4, and comprising: a ¼ waveretarder plate disposed between a pair of glass plates (multiplexors)bearing mirror and beam-splitter coatings as shown, so as to opticallymultiplex an input laser beam into four spatial-coherence reduced outputlaser beams, for subsequent planarization a multi-cylinderplanarizing-type illumination lens array disposed in close proximitytherewith. Functionality of the optical multiplexor is extended with theaddition of another beam splitting coating to further double the numberof laser beams produced during operation. This design would have adespeckling affectivity equivalent to eighteen (18) effectiveillumination sources. Extending the multiplexor one more cycle (to 6beams) would increase the number of effective laser sources to nearlytwenty-six (26).

Eighth Illustrative Embodiment of the Laser Beam OMUX Device of thePresent Invention

FIG. 5W6 shows an eighth illustrative embodiment of a multi-stage laserbeam despeckling device of the present invention. As shown, this deviceis constructed as hybrid OMUX subsystem comprising: a first laser beamOMUX module as shown in FIG. 5W2 to optically multiplex an input laserbeam into a pair of temporal/spatial coherence-reduced output laser beamthat spatially overlap each other as the output surface of the module;and a second OMUX despeckling module, as shown in FIG. 5O, for receivingthe output beam from the first module, and transmitting the beam throughthe second despeckling module so as to produce, as output, a pluralityof spatial/temporal coherence-reduced laser beams, for subsequentplanarization a multi-cylinder planarizing-type illumination lens arraydisposed in close proximity therewith. In this embodiment, the firstOMUX module (i.e. cube beam splitter) is used with a polarizationreflector to create the change in polarization. The second OMUX moduleis extended with the addition of another beam splitting coating tofurther double the number of output laser beams produced. This designwould have a despeckling affectivity equivalent to nearly thirteen (13)effective illumination sources.

Illustrative Embodiment of HFM-OMUX Based Planar Laser Illumination andImaging (PLIIM) Module of the Present Invention Employing IntegratedHFM-OMUX Based Despeckler

In FIGS. 5X1 through 5X4, an illustrative embodiment of the HFM-OMUXbased planar laser illumination and imaging (PLIIM) module is shownremoved from its PC board (shown in FIG. 5X1), and supporting both VLDsand IR laser diodes, a field of view (FOV) forming optics and FOVfolding mirror for use with the digital linear image detecting arraymounted on the PC board. In FIG. 5X4, the PLIIM module is shown mountedon its PC board supporting the digital linear image detection chip (i.e.linear or narrow-area image sensor), HFM and current drive circuitry,image capture and buffer circuitry, subsystem control circuitry (e.g.programmed micro-controller etc).

In FIG. 5Y, the PLIIM module depicted in FIG. 5X4 is shown arranged witha pair of PLIB/FOV folding mirrors used to direct the coplanar PLIB/FOVin a direction required by the system in which the PLIIM module isemployed.

Digital Imaging System of Illustrative Embodiment EmployingImaging-Based Object Motion and Velocity Sensing Technology

System embodiments, shown in FIGS. 6 through 6I, and 8A through 8A4,employ imaging-based object motion and velocity sensing technology,whereas other system embodiments shown in FIGS. 7B through 7E employPulse-Doppler LIDAR based object motion and velocity detectiontechniques provided at either a global or local subsystem level.

In other illustrative embodiments the Object Motion/Velocity DetectionState of operation is supported at the respective coplanar illuminationand imaging stations using globally provided image processors to computeobject motion and velocity data, which, in turn, is used to producecontrol data for controlling the linear and/area image sensing arraysemployed at the image formation and detection (IFD) subsystems of eachstation in the system.

In yet other embodiments, the Object Motion/Velocity Detection State canbe supported by a combination of both locally and globally providedcomputational resources, in a hybrid sort of an arrangement.

In the preferred illustrative embodiments, the Bar Code Reading State ofoperation of each illumination and imaging subsystem is computationallysupported by a globally provided or common/shared multi-processor imageprocessing subsystem 20. However, in other illustrative embodiments, thebar code reading functions of each station can be implemented locallyusing local image-processors locally accessible by each station.

In the illustrative embodiments of the present invention, the states ofoperation of each station 15 in the system 10 can be automaticallycontrolled using a variety of control methods.

One method, shown in FIGS. 6F1, 6G1A and 61B, supports a distributedlocal control process in the stations, wherein at each illumination andimaging station, the local control subsystem controls the function andoperation of the components of the illumination and imaging subsystem,and sends “state” data to the global control subsystem for statemanagement at the level of system operation. Using this method, only theillumination and imaging stations that detect an object in their fieldof view (FOV), as an object is moved through the 3D imaging volume ofthe system, will be automatically locally driven to their imagecapturing and processing “bar code reading state”, whereas all otherstations will remain in their object motion/velocity detection stateuntil they detect the motion of the object passing through their localFOV.

In the case where IR Pulse-Doppler LIDAR Pulse-Doppler sensingtechniques are used to implement one or more object motion/velocitydetection subsystems in a given system of the present invention, asshown in FIGS. 7B through 7E, this method of system control can providean ultimate level of illumination control, because visible illuminationis only generated and directed onto an object when the object isautomatically detected within the field of view of the station, thuspermitting the object to receive and block incident illumination fromreaching the eyes of the system operator or consumers who may bestanding at the point of sale (POS) station where the system has beeninstalled. In the case where imaging-based techniques are used toimplement one or more object motion/velocity detection subsystems in agiven system of the present invention, as shown in FIGS. 6 through 6E4,this method of system control can provide a very high level ofillumination control, provided that low levels of visible illuminationare only generated and directed onto an object during the ObjectMotion/Velocity Detection State.

A second possible method supports a distributed local control process inthe stations, with global over-riding of nearest neighboring stations inthe system. As shown in FIGS. 6F2, and 6G2A and 6G2B, each local controlsubsystem controls the function and operation of the components of itsillumination and imaging subsystem, and sends state data to the globalcontrol subsystem for state management at the level of system operation,as well as for over-riding the control functions of local controlsubsystems employed within other illumination and imaging stations inthe system. This method allows the global control subsystem to drive oneor more other nearest-neighboring stations in the system to the bar codereading state upon receiving state data from a local control subsystemthat an object has been detected and its velocity computed/estimated.This way, all neighboring stations near the detected object areautomatically driven to their image capturing and processing “bar codereading state” upon detection by only one station. This method providesa relatively high level of illumination control, because visibleillumination is generated and directed into regions of the 3D imagingvolume wherewithin the object is automatically detected at any instantin time, and not within those regions where the object is not expectedto be given its detection by a particular illumination and imagingstation.

A third possible method also supports distributed local control processin the stations, but with global over-riding of all neighboring stationsin the system. As shown in FIGS. 6F3, and 6G3A and 6G3B, each localcontrol subsystem controls the function and operation of the componentsof its illumination and imaging subsystem, and sends state data to theglobal control subsystem for state management at the level of systemoperation, as well as for over-riding the control functions of localcontrol subsystems employed within all neighboring illumination andimaging stations in the system. This method allows the global controlsubsystem to drive all neighboring stations in the system to the barcode reading state upon receiving state data from a single local controlsubsystem that an object has been detected and its velocitycomputed/estimated. This way, all neighboring stations, not just thenearest ones, are automatically driven to their image capturing andprocessing “bar code reading state” upon detection by only one station.This method provides a relatively high level of illumination control,because visible illumination is generated and directed into regions ofthe 3D imaging volume wherewithin the object is automatically detectedat any instant in time, and not within those regions where the object isnot expected to be given its detection by a particular illumination andimaging station.

Another fourth possible method supports a global control process. Asshown in FIGS. 8F and 8G, the local control subsystem in eachillumination and imaging station controls the operation of thesubcomponents in the station, except for “state control” which ismanaged at the system level by the global control subsystem using “statedata” generated by one or more object motion sensors (e.g. imagingbased, ultra-sonic energy based) provided at the system level within the3D Imaging Volume of the system, in various possible locations. Whenusing this method of global control, one or more Pulse-Doppler (IR)LIDAR subsystems (or even Pulse-Doppler SONAR subsystems) can bedeployed in the system so that real-time object motion and velocitysensing can be achieved within the 3D imaging volume, or across a majorsection or diagonal thereof. Employing this method, captured objectmotion and velocity data can be used to adjust the illumination and/orexposure control parameters therein (e.g. the frequency of the clocksignal used to read out image data from the linear image sensing arraywithin the IFD subsystem in the station).

By continuously collecting or receiving updated motion and velocity dataregarding objects present within 3-D imaging volume of the system, eachillumination and imaging station is able to generate control datarequired to optimally control exposure and/or illumination controloperations at the image sensing array of each illumination and imagingstation employed within the system. Also, the system control processtaught in Applicants' copending U.S. application Ser. No. 11/408,268,incorporated herein by reference, can also be used in combination withthe system of the present invention to form and detect digital imagesduring all modes of system operation using even the lowest expectedlevels of ambient illumination found in typical retail storeenvironments.

In general, each coplanar illumination and imaging station 15 is able toautomatically change its state of operation from Object Motion andVelocity Detection to Bar Code Reading in response to automateddetection of an object with at least a portion of the FOV of itscoplanar illumination and imaging plane. By virtue of this feature ofthe present invention, each coplanar illumination and imaging station inthe system is able to automatically and intelligently direct LED or VLDillumination at an object only when and for so long as the object isdetected within the FOV of its coplanar illumination and imaging plane.This intelligent capacity for local illumination control maximizesillumination being directed towards objects to be imaged, and minimizesillumination being directed towards consumers or the system operatorduring system operation in retail store environments, in particular.

In order to support automated object recognition functions (e.g.vegetable and fruit recognition) at the POS environment, image capturingand processing based object recognition subsystem 21 (i.e. includingObject Libraries etc.) cooperates with the multi-channel imageprocessing subsystem 20 so as to (i) manage and process the multiplechannels of digital image frame data generated by the coplanarillumination and imaging stations 15, (ii) extract object features fromprocessed digital images, and (iii) automatically recognize objects atthe POS station which are represented in the Object Libraries of theobject recognition subsystem 21.

In the illustrative embodiments, the omni-directional image capturingand processing based bar code symbol reading system module of thepresent invention includes an integrated electronic weigh scale module22, as shown in FIGS. 2A through 2C, which has a thin, tablet-like formfactor for compact mounting in the countertop surface of the POSstation. In addition to a complex of linear (or narrow-area) imagesensing arrays, area-type image sensing arrays may also be used incombination with linear image sensing arrays in constructingomni-directional image capturing and processing based bar code symbolreading systems in accordance with the present invention, as shown inFIGS. 10 through 14G.

While laser illumination (e.g. VLD) sources have many advantages forgenerating coplanar laser illumination planes for use in the imagecapture and processing systems of the present invention (i.e. excellentpower density and focusing characteristics), it is understood thatspeckle-pattern noise reduction measures will need to be practiced inmost applications. In connection therewith, the advanced speckle-patternnoise mitigation methods and apparatus disclosed in Applicants' U.S.Pat. No. 7,028,899 B2, incorporated herein by reference in its entiretyas if fully set forth herein, can be used to substantially reduce theruns power of speckle-noise power in digital imaging systems of thepresent invention employing coherent illumination sources.

In contrast, LED-based illumination sources can also be used as well togenerate planar illumination beams (planes) for use in the image captureand processing systems of the present invention. Lacking high temporaland spatial coherence properties, the primary advantage associated withLED technology is lack of speckle-pattern noise. Some significantdisadvantages with LED technology are the inherent limitations infocusing characteristics, and power density generation. Many of theselimitations can be addressed in conventional ways to make LED arrayssuitable for use in the digital image capture and processing systems andmethods of the present invention.

In some embodiments, it may be desired to use both VLD and LED basedsources of illumination to provide hybrid forms of illumination withinthe imaging-based bar code symbol reading systems of the presentinvention.

Having provided an overview on the system and methods of the presentinvention, it is appropriate at this juncture to now describe thevarious illustrative embodiments thereof in greater technical detail.

Illustrative Embodiment of the Omni-Directional Image Capturing andProcessing Based Bar Code Symbol Reading System of the PresentInvention, Employing Plurality of Object Motion/Velocity Detectors inSystem

In FIGS. 2 through 5F, an illustrative embodiment of theomni-directional image capturing and processing based bar code symbolreading system of the present invention 10 is shown integrated withelectronic weigh scale 22, having a thin, tablet-like form factor forcompact mounting in the countertop surface 2 of the POS station 1. Asshown in FIG. 2A, imaging window protection plate 17 has a central Xaperture pattern and a pair of parallel apertures aligned parallel tothe sides of the system. These apertures permit the projection of aplurality of coplanar illumination and imaging planes 55 from a complexof coplanar illumination and imaging stations 15A through 15F mountedbeneath the imaging window of the system. The primary functions of eachcoplanar laser illumination and imaging station 15 is to generate andproject coplanar illumination and imaging planes 55 through the imagingwindow 13 and apertures 18 into the 3D imaging volume 16 of the system,and capture digital linear (1D) digital images along the field of view(FOV) of these illumination and linear imaging planes. These capturedlinear images are then buffered and decode-processed using linear (1D)type image capturing and processing based bar code reading algorithms,or can be assembled together to reconstruct 2D images fordecode-processing using 1D/2D image processing based bar code readingtechniques.

In FIG. 2A, the apertured imaging window protection plate 17 is showneasily removed from over the glass imaging window 13 of theomni-directional image capturing and processing based bar code symbolreading system, during routine glass imaging window cleaning operations.

As shown in FIGS. 2B and 2C, the image capturing and processing module56 (having a thin tablet form factor and including nearly all subsystemsdepicted in FIGS. 5A, except scale module 22) is shown lifted off andaway from the electronic weigh scale module 22 during normal maintenanceoperations. In this configuration, the centrally located load cell 23 isrevealed along with the touch-fit electrical interconnector arrangement57 of the present invention that automatically establishes allelectrical interconnections between the two modules when the imagecapturing and processing module 56 is placed onto the electronic weighscale module 22, and its electronic load cell 23 bears substantially allof the weight of the image capturing and processing module 5.

In FIG. 2D, the load cell 23 of the electronic weigh scale module 22 isshown to directly bear all of the weight of the image capturing andprocessing module 56 (and any produce articles placed thereon duringweighing operations), while the touch-fit electrical interconnectorarrangement of the present invention 57 automatically establishes allelectrical interconnections between the two modules.

In FIGS. 3A through 3F, the spatial arrangement of coplanar illuminationand imaging planes are described in great detail for the illustrativeembodiment of the present invention. The spatial arrangement and layoutof the coplanar illumination and imaging stations within the systemhousing is described in FIGS. 4A through 5F. As shown, all coplanarillumination and imaging stations, including their optical andelectronic-optical components, are mounted on a single printed-circuit(PC) board 58, mounted in the bottom portion of the system housing, andfunctions as an optical bench for the mounting of image sensing arrays,VLDs or LEDs, beam shaping optics, field of view (FOV) folding mirrorsand the like, as indicated in FIGS. 4A through 5F.

The First Illustrative Embodiment of the Omni-Directional ImageProcessing Based Bar Code Symbol Reading System of the PresentInvention, Employing Plurality of Imaging-Based Object Motion/VelocityDetectors in System

As shown in FIG. 6, each coplanar illumination and imaging planeprojected within the 3D imaging volume of the system of the firstillustrative embodiment has at least one spatially-co-extensiveimaging-based object motion and velocity “field of view”, that issupported by an imaging-based object motion/velocity detection subsystemin the station generating the coplanar illumination and imaging plane.The field of view of the imaging-based motion/velocity detectionsubsystem is supported during the Object Motion/Velocity Detection Modeof the station, and can be illuminated by ambient illumination, orillumination from VLDs and/or LEDs of the motion/velocity detectionsubsystem 49 of the image formation and detection subsystem 40. Thefunction of the object motion/velocity detection field is to enableautomatic control of illumination and exposure during the Bar CodeReading Modes of the stations in the system.

In FIG. 6B, the system architecture of the omni-directional imagecapturing and processing based bar code symbol reading system of FIG. 2is shown comprising: a complex of coplanar illuminating and linearimaging stations 15A′ through 15F′, constructed using linear theillumination arrays and image sensing arrays shown in FIGS. 6A and 6B; amulti-processor (multi-channel) image processing subsystem 20 forsupporting automatic image processing based bar code symbol reading andoptical character recognition (OCR) along each coplanar illumination andimaging plane within the system, which corresponds to a single channelof the subsystem 20; a software-based object recognition subsystem 21,for use in cooperation with the image processing subsystem 20, andautomatically recognizing objects (such as vegetables and fruit) at theretail POS while being imaged by the system; an electronic weight scale22 employing one or more load cells 23 positioned centrally below thesystem housing, for rapidly measuring the weight of objects positionedon the window aperture of the system for weighing, and generatingelectronic data representative of measured weight of the object; aninput/output subsystem 28 for interfacing with the image processingsubsystem, the electronic weight scale 22, RFID reader 26, credit-cardreader 27 and Electronic Article Surveillance (EAS) Subsystem 28(including EAS tag deactivation block integrated in system housing, anda Checkpoint® EAS antenna); a wide-area wireless interface (WIFI) 31including RF transceiver and antenna 31A for connecting to the TCP/IPlayer of the Internet as well as one or more image storing andprocessing RDBMS servers 33 (which can receive images lifted by systemfor remote processing by the image storing and processing servers 33); aBlueTooth® RF 2-way communication interface 35 including RF transceiversand antennas 35A for connecting to Blue-tooth® enabled hand-heldscanners, imagers, PDAs, portable computers 36 and the like, forcontrol, management, application and diagnostic purposes; and a globalcontrol subsystem 37 for controlling (i.e. orchestrating and managing)the operation of the coplanar illumination and imaging stations (i.e.subsystems), electronic weight scale 22, and other subsystems. As shown,each coplanar illumination and imaging subsystem 15′ transmits frames ofimage data to the image processing subsystem 25, for state-dependentimage processing and the results of the image processing operations aretransmitted to the host system via the input/output subsystem 20. InFIG. 6B, the bar code symbol reading module employed along each channelof the multi-channel image processing subsystem 20 can be realized usingSwiftDecoder® Image Processing Based Bar Code Reading Software fromOmniplanar Corporation, New Jersey, or any other suitable imageprocessing based bar code reading software. Also, the system providesfull support for (i) dynamically and adaptively controlling systemcontrol parameters in the digital image capture and processing system,as disclosed and taught in Applicants' PCT Application Serial No. PCTUS2007/009763 entitled “METHOD OF AND APPARATUS FOR DYNAMICALLY ANDADAPTIVELY CONTROLLING SYSTEM CONTROL PARAMETERS IN A DIGITAL IMAGECAPTURE AND PROCESSING SYSTEM”, as well as (ii) permitting modificationand/or extension of system features and function, as disclosed andtaught in PCT Application No. WO 2007/075519 entitled DIGITAL IMAGECAPTURE AND PROCESSING SYSTEM PERMITTING MODIFICATION AND/OR EXTENSIONOF SYSTEM FEATURES AND FUNCTIONS, both of which are incorporated hereinby reference.

As shown in FIG. 6A, an array of VLDs or LEDS can be focused with beamshaping and collimating optics so as to concentrate their output powerinto a thin illumination plane which spatially coincides exactly withthe field of view of the imaging optics of the coplanar illumination andimaging station, so very little light energy is wasted.

Each substantially planar illumination beam (PLIB) can be generated froma planar illumination array (PLIA) formed by a plurality of planarillumination modules (PLIMs) using either VLDs or LEDs and associatedbeam shaping and focusing optics, taught in greater technical detail inApplicants U.S. patent application Ser. Nos. 10/299,098 filed Nov. 15,2002, now U.S. Pat. No. 6,898,184, and Ser. No. 10/989,220 filed Nov.15, 2004, each incorporated herein by reference in its entirety.Preferably, each planar illumination beam (PLIB) generated from a PLIMin a PLIA is focused so that the minimum width thereof occurs at a pointor plane which is the farthest object (or working) distance at which thesystem is designed to capture images within the 3D imaging volume of thesystem, although this principle can be relaxed in particularapplications to achieve other design objectives.

As shown in FIGS. 6B, 6C, 6D and 6E1, each coplanar illumination andimaging station 15′ employed in the system of FIGS. 2 and 6B comprises:an illumination subsystem 44′ including a linear array of VLDs or LEDs45 and associated focusing and cylindrical beam shaping optics (i.e.planar illumination arrays PLIAs), for generating a planar illuminationbeam (PLIB) 61 from the station; a linear image formation and detection(IFD) subsystem 40 having a camera controller interface (e.g. realizedas a field programmable gate array or FPGA) for interfacing with thelocal control subsystem 50, and a high-resolution linear image sensingarray 41 with optics 42 providing a field of view (FOV) 43 on the imagesensing array that is coplanar with the PLIB produced by the linearillumination array 45, so as to form and detect linear digital images ofobjects within the FOV of the system; a local control subsystem 50 forlocally controlling the operation of subcomponents within the station,in response to control signals generated by global control subsystem 37maintained at the system level, shown in FIG. 6B; an image capturing andbuffering subsystem 48 for capturing linear digital images with thelinear image sensing array 41 and buffering these linear images inbuffer memory so as to form 2D digital images for transfer toimage-processing subsystem 20 maintained at the system level, as shownin FIG. 6B, and subsequent image processing according to bar code symboldecoding algorithms, OCR algorithms, and/or object recognitionprocesses; a high-speed image capturing and processing basedmotion/velocity sensing subsystem 49′ for motion and velocity data tothe local control subsystem 50 for processing and automatic generationof control data that is used to control the illumination and exposureparameters of the linear image formation and detection system within thestation. Details regarding the design and construction of planarillumination and imaging module (PLIIMs) can be found in Applicants'U.S. Pat. No. 7,028,899 B2, incorporated herein by reference.

As shown in FIGS. 6D, 6E1, the high-speed image capturing and processingbased motion/velocity sensing subsystem 49′ comprises: an area-typeimage acquisition subsystem 65 with an area-type image sensing array andoptics shown in FIG. 6D for generating a field of view (FOV) that ispreferably spatially coextensive with the longer dimensions of the FOV43 of the linear image formation and detection subsystem 40 as shown inFIG. 6B; an area-type (IR) illumination array 66 for illuminating theFOV of motion/velocity detection subsystem 49′; and an embedded digitalsignal processing (DSP) image processor 67, for automatically processing2D images captured by the digital image acquisition subsystem. The DSPimage processor 67 processes captured images so as to automaticallyabstract, in real-time, motion and velocity data from the processedimages and provide this motion and velocity data to the local controlsubsystem 50 for the processing and automatic generation of control datathat is used to control the illumination and exposure parameters of thelinear image formation and detection system within the station.

In the illustrative embodiment shown in FIGS. 2 through 6C, each imagecapturing and processing based motion/velocity sensing subsystem 49′continuously and automatically computes the motion and velocity ofobjects passing through the planar FOV of the station, and uses thisdata to generate control signals that set the frequency of the clocksignal used to read out data from the linear image sensing array 41employed in the linear image formation and detection subsystem 40 of thesystem. In FIGS. 6E2 and 6E3, two versions of the image capturing andprocessing based motion/velocity sensing subsystem 49′ of FIG. 6E1 areschematically illustrated, in the context of (i) capturing images ofobjects passing through the FOV of the image formation and detectionsubsystem 40, (ii) generating motion and velocity data regarding theobjects, and (iii) controlling the frequency of the clock signal used toread out data from the linear image sensing array 41 employed in thelinear image formation and detection subsystem 40 of the system.

In FIG. 6E3, the image capturing and processing based motion/velocitysensing subsystem 49′ employs an area-type image sensing array 69 tocapture images of objects passing through the FOV of the linear imageformation and detection subsystem 40. Then, DSP-based image processor 67computes motion and velocity data regarding object(s) within the FOV ofthe linear image formation and detection subsystem 40, and this motionand velocity data is then provided to the local subsystem controller 50so that it can generate (i.e. compute) control data for controlling thefrequency of the clock signal used in reading data out of the linearimage sensing array of the image formation and detection subsystem. Analgorithm for computing such control data, based on sensed 2D images ofobjects moving through (at least a portion of) the FOV of the linearimage formation and detection subsystem 40, will now be described indetail below with reference to the process diagram described in FIG.6E2, and the schematic diagram set forth in FIG. 6E3.

As indicated at Blocks A, B and C in FIG. 6E2, object motion detected onthe linear sensing array of the IFD subsystem (dX, dY) is calculatedfrom the motion detected by images captured by the motion/velocitysensing subsystem (dX′, dY′) using the equations (1) and (2) as follows:

$\begin{matrix}{{dX} = {{F\left( {{dX}^{\prime},\theta_{p},n_{1},p_{1},n_{2},p_{2}} \right)} = {\frac{n_{2}p_{2}}{n_{1}p_{1}}\left( {{{dX}^{\prime}\cos \; \theta_{p}} - {{dY}^{\prime}\sin \; \theta_{p}}} \right)}}} & (1) \\{{dY} = {{F\left( {{dY}^{\prime},\theta_{p},n_{1},p_{1},n_{2},p_{2}} \right)} = {\frac{n_{2}p_{2}}{n_{1}p_{1}}\left( {{{dX}^{\prime}\sin \; \theta_{p}} + {{dY}^{\prime}\cos \; \theta_{p}}} \right)}}} & (2)\end{matrix}$

whereθ_(p) is the projection angle, which is the angle between themotion/velocity detection subsystem 49′ (dX′, dY′) and the linear imagesensing array 41 in the IFD subsystem 40 (dX,dY),n₁ is the pixel number of the image sensing array in the motion/velocitydetection subsystem,p₁ is the size of image sensing element 69 in the motion/velocitydetection subsystem 49′ in FIG. 6D,n₂ is the pixel number of the linear image sensing array 41 employed inthe image formation and detection subsystem 40, andp₂ is the pixel size of the linear image sensing array 41 employed inthe image formation and detection (IFD) subsystem 40.As indicated at Block D in FIG. 6E2, the velocity of the object on thelinear sensing array 41 of the IFD subsystem is calculated usingEquations Nos. (3), (4), (5) below:

$\begin{matrix}{V_{x} = \frac{X}{t^{\prime}}} & (3) \\{V_{y} = \frac{Y}{t^{\prime}}} & (4) \\{\theta = {\arctan\left( \frac{V_{y}}{V_{x}} \right)}} & (5)\end{matrix}$

where dt′ is the timing period from the motion/velocity sensingsubsystem illustrated in FIG. 6D. As indicated at Block E in FIG. 6E2,the frequency of the clock signal f in the IFD subsystem is computedusing a frequency control algorithm which ideally is expressed as afunction of the following system parameters:

f=H(p ₂ ,V _(x) ,V _(y) ,θ,dt′)

While there are various possible ways of formulating the frequencycontrol algorithm, based on experiment and/or theoretic study, thesimplest version of the algorithm is given expression No. (6) below:

$\begin{matrix}{f = \frac{V_{y}}{{kp}_{2}}} & (6)\end{matrix}$

where k is a constant decided by the optical system providing the FOV ofthe image capturing and processing based motion/velocity detectionsubsystem 49′, illustrated in FIG. 6D.

As indicated at Block F, the frequency of the clock signal used to clockdata out from the linear image sensing array in the IFD subsystem isthen adjusted using the computed clock frequency f.

In FIG. 6E4, the image capturing and processing based motion/velocitydetection subsystem 49′ employs a linear-type image sensing array 70 tocapture images of objects passing through the FOV of the linear imageformation and detection subsystem. Then, DSP-based image processor 67computes motion and velocity data regarding object(s) within the FOV ofthe linear image formation and detection (IFD) subsystem 40, and thismotion and velocity data is then provided to the local subsystemcontroller 50 so that it can generate (i.e. compute) control data forcontrolling the frequency of the clock signal used in reading data outof the linear image sensing array of the image formation and detectionsubsystem. The frequency control algorithm described above can be usedto control the clock frequency of the linear image sensing array 41employed in the IFD subsystem 40 of the system.

While the system embodiments of FIGS. 6E2, 6E3 and 6E4 illustratecontrolling the clock frequency in the image formation and detectionsubsystem 40, it is understood that other camera parameters, relating toexposure and/or illumination, can be controlled in accordance with theprinciples of the present invention.

When any one of the coplanar illumination and imaging stations isconfigured in its Object Motion/Velocity Detection State, there is theneed to illuminate to control the illumination that is incident upon theimage sensing array employed within the object motion/velocity detectorsubsystem 49′ shown in FIGS. 6C and 6D. In general, there are severalways to illuminate objects during the object motion/detection mode (e.g.ambient, laser, LED-based), and various illumination parameters can becontrolled while illuminating objects being imaged by the image sensingarray 41 of the object motion/velocity detection subsystem 49′ employedat any station in the system. Also, given a particular kind ofillumination employed during the Object Motion/Velocity Detection Mode,there are various illumination parameters that can be controlled,namely: illumination intensity (e.g. low-power, half-power, full power);illumination beam width (e.g. narrow beam width, wide beam width); andillumination beam thickness (e.g. small beam thickness, large beamthickness). Based on these illumination control parameters, severaldifferent illumination control methods can be implemented at eachillumination and imaging station in the system.

For example, methods based illumination source classification includethe following: (1) Ambient Control Method, wherein ambient lighting isused to illuminate the FOV of the image sensing array 69, 70 in theobject motion/velocity detecting subsystem 49′ subsystem/system duringthe object motion/velocity detection mode and bar code symbol readingmode of subsystem operation; (2) Low-Power Illumination Method, whereinillumination produced from the LED or VLD array of a station is operatedat half or fractional power, and directed into the field of view (FOV)of the image sensing array employed in the object motion/velocitydetecting subsystem 49′; and (3) Full-Power Illumination Method, whereinillumination is produced by the LED or VLD array of the station—operatedat half or fractional power—and directed in the field of view (FOV) ofthe image sensing array employed in the object motion/velocity detectingsubsystem 49′.

Methods based on illumination beam thickness classification include thefollowing: (1) Illumination Beam Width Method, wherein the thickness ofthe planar illumination beam (PLIB) is increased so as to illuminatemore pixels (e.g. 3 or more pixels) on the image sensing array of theobject motion/velocity detecting subsystem 49′ when the station isoperated in Object Motion/Velocity Detection Mode. This method will beuseful when illuminating the image sensing array of the objectmotion/velocity detecting subsystem 49′ using, during the Bar CodeReading Mode, planar laser or LED based illumination having a narrowbeam thickness, insufficient to illuminate a sufficient number of pixelrows in the image sensing array of the motion/velocity detector 49.

Three different methods are disclosed below for controlling theoperations of the image capture and processing system of the presentinvention. These methods will be described below.

The first method, described in FIGS. 6F1 and 6G1A and 6G1B, can bethought of as a Distributed Local Control Method, wherein at eachillumination and imaging station, the local control subsystem 50controls the function and operation of the components of theillumination and imaging subsystem 50, and sends state data to theglobal control subsystem for “state management” at the level of systemoperation, but not “state control”, which is controlled by the localcontrol system. As used herein, the term “state management” shall meanto keep track of or monitoring the state of a particular station,whereas the term “state control” shall mean to determine or dictate theoperational state of a particular station at an moment in time.

The second control method described in FIGS. 6F2, 6G2A and 6G2B can bethought of as a Distributed Local Control Method with GlobalNearest-Neighboring Station Over-Ride Control, wherein the local controlsubsystems 50 start out controlling their local functions and operationsuntil an object is detected, whereupon the local control subsystemautomatically sends state data to the global control subsystem for statemanagement at the level of system operation, as well as for over-ridingthe control functions of local control subsystems employed within otherillumination and imaging stations in the system. This method allows theglobal control subsystem 37 to drive one or more other stations in thesystem to the bar code reading state upon receiving state data when alocal control subsystem has detected an object and its motion andvelocity are computed/estimated. This global control subsystem 37 candrive “nearest neighboring” stations in the system to their bar codereading state (i.e. image capturing and decode-processing) as in thecase of FIGS. 6F3, 6G3A and 6G3B.

The third control method described in FIGS. 6F3, 6G3A and 6G3B can bethought of as a Distributed Local Control Method with Global AllNeighboring Station Over-Ride Control, wherein the local controlsubsystems start out controlling their local functions and operationsuntil an object is detected, whereupon the local control subsystem 50automatically sends state data to the global control subsystem 37 forstate management at the level of system operation, as well as forover-riding the control functions of local control subsystems employedwithin other illumination and imaging stations in the system. Thismethod allows the global control subsystem 37 to drive one or more otherstations in the system to the bar code reading state upon receivingstate data when a local control subsystem has detected an object and itsmotion and velocity are computed/estimated. This global controlsubsystem can drive “all neighboring” stations in the system to theirbar code reading state (i.e. image capturing and decode-processing) asin the case of FIGS. 6F3, 6G3A and 6G3B.

The fourth system control method, described in FIGS. 8F and 8G, can bethrough of as a Global Control Method, wherein the local controlsubsystem in each illumination and imaging station controls theoperation of the subcomponents in the station, except for “statecontrol” which is managed at the system level by the global controlsubsystem 37 using “state data” generated by one or more object motionsensors (e.g. imaging based, ultra-sonic energy based) provided at thesystem level within the 3D imaging volume of the system, in variouspossible locations. When using this method of control, it might bedesirable to deploy imaging-based object motion and velocity sensors asshown in FIG. 8A, or IR Pulse-Doppler LIDAR sensors as shown in FIG. 8B,or even ultrasonic Pulse-Doppler SONAR sensors as applications mayrequire, so that real-time object motion and velocity sensing can beachieved within the entire 3D imaging volume, or across one or moresections or diagonals thereof. With such provisions, object motion andvelocity data can be captured and distributed (in real-time) to eachillumination and imaging station (e.g. via the global control subsystem37) for purposes of adjusting the illumination and/or exposure controlparameters therein (e.g. the frequency of the clock signal used to readout image data from the linear image sensing array within the IFDsubsystem in each station) during system operation.

Having described four primary classes of control methods that might beused to control the operations of systems of the present invention, itis appropriate at this juncture to describe the first three systemcontrol methods in greater technical detail, with reference tocorresponding state transition diagrams and system flow control charts.

As shown in FIG. 6F1, a state transition diagram is provided for theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 6 and 6C, running the system controlprogram described in flow charts of FIGS. 6G1A and 6G1B, withlocally-controlled imaging-based object motion/velocity detectionprovided in each coplanar illumination and imaging subsystem of thesystem, as illustrated in FIG. 6. The flow chart of FIGS. 6G1A and 6G1Bdescribes the operations (i.e. tasks) that are automatically performedduring the state control process of FIG. 6F1, which is carried outwithin the omni-directional image capturing and processing based barcode symbol reading system described in FIGS. 6 and 6C.

At Step A in FIG. 6G1A, upon powering up the Omni-Directional Imagecapturing and processing based Bar Code Symbol Reading System (“System”)10A, and/or after each successful read of a bar code symbol thereby, theglobal control subsystem initializes the system by preconfiguring eachCoplanar Illumination and Imaging Station employed therein in its ObjectMotion/Velocity Detection State.

As indicated at Step B in FIG. 6G1A, at each Coplanar Illumination andImaging Station 15′ currently configured in its Object Motion/VelocityDetection State, the object motion/velocity detection subsystem 49′continuously captures linear (1D) images along the Imaging-Based ObjectMotion/Velocity Detection Field of the station (coincident with the FOVof the IFD subsystem) and automatically processes these captured imagesso as to automatically detect the motion and velocity of an object beingpassed through the 3D imaging volume of the station and generate datarepresentative thereof. From this data, the local control subsystemgenerates control data for use in controlling the exposure and/orillumination processes at coplanar illumination and imaging station(e.g. the frequency of the clock signal used in the IFD subsystem).

During the Object Motion/Velocity Detection State, the motion/velocitydetection subsystem 49′ provided at each coplanar illumination andimaging station can capture 2D images of objects within the 3D imagingvolume, using ambient lighting, or using lighting generated by the (VLDand/or LED) illumination arrays employed in either the objectmotion/velocity detection subsystem 49′ or within the illuminationsubsystem itself. In the event illumination sources within theillumination subsystem are employed, then these illumination arrays aredriven at the lowest possible power level so as to not produce effectsthat are visible or conspicuous to consumers who might be standing atthe POS, near the system of the present invention.

As indicated at Step C in FIG. 6G1A, for each Coplanar Illumination andImaging Station 15′ that automatically detects an object moving throughor within its Imaging-based Object Motion/Velocity Detection Field, itslocal control subsystem 50 automatically configures the coplanarillumination and imaging station into its Imaging-Based Bar Code ReadingMode (State).

During the Imaging-Based Bar Code Reading Mode (State), the illuminationarrays of the illumination subsystem 44 are preferably driven at fullpower. Optionally, in some applications, the object motion/velocitydetection subsystem can be permitted to simultaneously collect (duringthe bar code reading state) updated object motion and sensing data fordynamically controlling the exposure and illumination parameters of theIFD Subsystem 40.

As indicated at Step D in FIG. 6G1B, from each coplanar illumination andimaging station currently configured in its Imaging-Based Bar CodeSymbol Reading State, the station automatically illuminates the detectedobject, with laser or VLD illumination (as the case may be), andcaptures and buffers digital 1D images thereof, and transmits thesereconstructed 2D images to the global multi-processor image processingsubsystem 20 for processing these buffered images so as to read a 1D or2D bar code symbol represented in the images.

As indicated at Step E of FIG. 6G1B, upon the 1D or 2D bar code symbolbeing successfully read by at least one of the coplanar illumination andimaging stations in the system, the image processing subsystem 20automatically generates symbol character data representative of the readbar code symbol, transmits the symbol character data to the input/outputsubsystem, and the global control subsystem reconfigures each coplanarillumination and imaging station back into its Object Motion/VelocityDetection State and returns to Step B, so that the system can resumedetection of object motion and velocity within the 3D imaging volume ofthe system.

As indicated at Step F in FIG. 6G1B, upon failure to read at least 1D or2D bar code symbol within a predetermined time period (from the time anobject has been detected within the 3D imaging volume), the localcontrol subsystem 50 reconfigures the coplanar illumination and imagingstation to its Object Motion and Velocity Detection State at Step B, tocollect and update object motion and velocity data (and derive controldata for exposure and/or illumination control).

As shown in FIG. 6F2, a state transition diagram is provided for theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 6 and 6C, running the system controlprogram described in flow charts of FIGS. 6G2A and 6G2B, employinglocally-controlled object motion/velocity detection in each coplanarillumination and imaging subsystem of the system, withglobally-controlled over-driving of nearest-neighboring stations. Theflow chart of FIGS. 6G2A and 6G2B describes the operations (i.e. tasks)that are automatically performed during the state control process ofFIG. 6F2, which is carried out within the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIGS. 6 and 6C.

At Step A in FIG. 6G2A, upon powering up the Omni-Directional Imagecapturing and processing based Bar Code Symbol Reading System(“System”), and/or after each successful read of a bar code symbolthereby, the global control subsystem initializes the system bypre-configuring each Coplanar Illumination and Imaging Station employedtherein in its Object Motion/Velocity Detection State.

As indicated at Step B in FIG. 6G2A, at each Coplanar Illumination andImaging Station currently configured in its Object Motion/VelocityDetection State, the object motion/velocity detection subsystem 49′continuously captures linear (1D) images along the Imaging-Based ObjectMotion/Velocity Detection Field of the station (coincident with the FOVof the IFD subsystem) and automatically processes these captured imagesso as to automatically detect the motion and velocity of an object beingpassed through the 3D imaging volume of the station and generate datarepresentative thereof. From this data, the local control subsystemgenerates control data for use in controlling the exposure and/orillumination processes at coplanar illumination and imaging station(e.g. the frequency of the clock signal used in the IFD subsystem).

During the Object Motion/Velocity Detection State, the motion/velocitydetection subsystem 49′ can capture 2D images of objects within the 3Dimaging volume, using ambient lighting, or using lighting generated bythe (VLD and/or LED) illumination arrays, employed in either the objectmotion/velocity detection subsystem 49′ or within the illuminationsubsystem. In the event illumination sources within the illuminationsubsystem are employed, then these illumination arrays are driven at thelowest possible power level so as to not produce effects that arevisible or conspicuous to consumers who might be standing at the POS,near the system of the present invention.

As indicated at Step C in FIG. 6G2A, for each Coplanar Illumination andImaging Station that automatically detects an object moving through orwithin its Imaging-based Object Motion/Velocity Detection Field, itslocal control subsystem 50 automatically configures the CoplanarIllumination and Imaging Station into its Imaging-Based Bar Code ReadingMode (State), and transmits “state data” to the global control subsystemfor automatically over-driving “nearest neighboring” coplanarillumination and imaging subsystems into their Bar Code Reading State.

During the Imaging-Based Bar Code Reading Mode (State), the illuminationarrays of the illumination subsystem 44 at the station are preferablydriven at full power. Optionally, in some applications, the objectmotion/velocity detection subsystem 49′ can be permitted tosimultaneously collect (during the Bar Code Reading State) updatedobject motion and velocity data, for use in dynamically controlling theexposure and illumination parameters of the IFD Subsystem.

As indicated at Step D in FIG. 6G2B, from each Coplanar Illumination andImaging Station currently configured in its Imaging-Based Bar CodeSymbol Reading State, the station automatically illuminates the detectedobject with laser or VLD illumination (as the case may be), and capturesand buffers digital 1D images thereof, and then transmits reconstructed2D images to the global multi-processor image processing subsystem 20(or a local image processing subsystem in some embodiments) forprocessing these buffered images so as to read a 1D or 2D bar codesymbol represented in the images.

As indicated at Step E of FIG. 6G2B, upon a 1D or 2D bar code symbolbeing successfully read by at least one of the Coplanar Illumination andImaging Stations in the system, the image processing subsystemautomatically generates symbol character data representative of the readbar code symbol, transmits the symbol character data to the input/outputsubsystem, and the global control subsystem 37 then reconfigures eachCoplanar Illumination and Imaging Station back into its ObjectMotion/Velocity Detection State (and returns to Step B) so that thesystem can resume automatic detection of object motion and velocitywithin the 3D imaging volume of the system.

As indicated at Step F in FIG. 6G2B, upon failure to read at least 1D or2D bar code symbol within a predetermined time period (from the time anobject has been detected within the 3D imaging volume), the localcontrol subsystem 50 reconfigures the coplanar illumination and imagingstation to its Object Motion and Velocity Detection State, to collectand update object motion and velocity data (and derive control data forexposure and/or illumination control), and then returns to Step B.

As shown in FIG. 6F3, a state transition diagram is provided for theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 2, 6 and 6C, running the systemcontrol program described in flow charts of FIGS. 6G3A and 6G3B,employing locally-controlled object motion/velocity detection in eachcoplanar illumination and imaging subsystem of the system, withglobally-controlled over-driving of all-neighboring stations. The flowchart of FIGS. 6G3A and 6G3B describes the operations (i.e. tasks) thatare automatically performed during the state control process of FIG.6F3, which is carried out within the omni-directional image capturingand processing based bar code symbol reading system described in FIGS. 6and 6C.

At Step A in FIG. 6G3A, upon powering up the Omni-Directional Imagecapturing and processing based Bar Code Symbol Reading System(“System”), and/or after each successful read of a bar code symbolthereby, the global control subsystem initializes the system bypre-configuring each Coplanar Illumination and Imaging Station employedtherein in its Object Motion/Velocity Detection State.

As indicated at Step B in FIG. 6G3A, at each Coplanar Illumination andImaging Station currently configured in its Object Motion/VelocityDetection State, the object motion/velocity detection subsystem 49′continuously captures linear (1D) images along the Imaging-Based ObjectMotion/Velocity Detection Field of the station (coincident with the FOVof the IFD subsystem) and automatically processes these captured imagesso as to automatically detect the motion and velocity of an object beingpassed through the 3D imaging volume of the station and generate datarepresentative thereof. From this data, the local control subsystemgenerates control data for use in controlling the exposure and/orillumination processes at coplanar illumination and imaging station(e.g. the frequency of the clock signal used in the IFD subsystem).

During the Object Motion/Velocity Detection State, the motion/velocitydetection subsystem 49′ can capture 2D images of objects within the 3Dimaging volume, using ambient lighting or light generated by the (VLDand/or LED) illumination arrays employed in either the objectmotion/velocity sensing subsystem or within the illumination subsystem.In the event illumination sources within the illumination subsystem areemployed, then these illumination arrays are preferably driven at thelowest possible power level so as to not produce effects that arevisible or conspicuous to consumers who might be standing at the POS,near the system of the present invention.

As indicated at Step C in FIG. 6G2A, for each Coplanar Illumination andImaging Station that automatically detects an object moving through orwithin its Imaging-based Object Motion/Velocity Detection Field, itslocal control subsystem 50 automatically configures the CoplanarIllumination and Imaging Station into its Imaging-Based Bar Code ReadingMode (State), and transmits “state data” to the global control subsystemfor automatically over-driving “all neighboring” coplanar illuminationand imaging subsystems into their Bar Code Reading State.

During the Imaging-Based Bar Code Reading Mode (State), the illuminationarrays of the illumination subsystem 44 are preferably driven at fullpower. Optionally, the object motion/velocity detection subsystem can bepermitted to simultaneously collect (during the Bar Code Reading State)updated object motion and sensing data for dynamically controlling theexposure and illumination parameters of the IFD Subsystem.

As indicated at Step D in FIG. 6G3B, from each Coplanar Illumination andImaging Station currently configured in its Imaging-Based Bar CodeSymbol Reading State, the station automatically illuminates the detectedobject, with laser or VLD illumination (as the case may be), andcaptures and buffers digital 1D images thereof, and transmits thesereconstructed 2D images to the global image processing subsystem 20 forprocessing these buffered images so as to read a 1D or 2D bar codesymbol represented in the images.

As indicated at Step E of FIG. 6G3B, upon the 1D or 2D bar code symbolbeing successfully read by at least one of the Coplanar Illumination andImaging Stations in the System, the image processing subsystemautomatically generates symbol character data representative of the readbar code symbol, transmits the symbol character data to the input/outputsubsystem, and the global control subsystem 37 reconfigures eachCoplanar Illumination and Imaging Station back into its ObjectMotion/Velocity Detection State and returns to Step B, so that thesystem can resume automatic detection of object motion and velocitywithin the 3D imaging volume of the system.

As indicated at Step F in FIG. 6G3B, upon failure to read at least 1D or2D bar code symbol within a predetermined time period (from the time anobject has been detected within the 3D imaging volume), the localcontrol subsystem 50 reconfigures the coplanar illumination and imagingstation to its Object Motion and Velocity Detection State at Step B, tocollect and update object motion and velocity data (and derive controldata for exposure and/or illumination control).

FIG. 6H describes an exemplary embodiment of a computing and memoryarchitecture platform that can be used to implement the omni-directionalimage capturing and processing based bar code symbol reading systemdescribed in FIGS. 6 and 6C. As shown, this hardware computing andmemory platform can be realized on a single PC board 58, along with theelectro-optics associated with the illumination and imaging stations andother subsystems described in FIG. 6G1A through 6G3B, and thereforefunctioning as an optical bench as well. As shown, the hardware platformcomprises: at least one, but preferably multiple high speed dual coremicroprocessors, to provide a multi-processor architecture having highbandwidth video-interfaces and video memory and processing support; anFPGA (e.g. Spartan 3) for managing the digital image streams supplied bythe plurality of digital image capturing and buffering channels, each ofwhich is driven by a coplanar illumination and imaging station (e.g.linear CCD or CMOS image sensing array, image formation optics, etc) inthe system; a robust multi-tier memory architecture including DRAM,Flash Memory, SRAM and even a hard-drive persistence memory in someapplications; arrays of VLDs and/or LEDs, associated beam shaping andcollimating/focusing optics; and analog and digital circuitry forrealizing the illumination subsystem; interface board withmicroprocessors and connectors; power supply and distribution circuitry;as well as circuitry for implementing the others subsystems employed inthe system.

FIG. 6I describes a three-tier software architecture that can run uponthe computing and memory architecture platform of FIG. 6H, so as toimplement the functionalities of the omni-directional image capturingand processing based bar code symbol reading system described FIGS. 6and 6C. Details regarding the foundations of this three-tierarchitecture can be found in Applicants' copending U.S. patent Ser. No.11/408,268, incorporated herein by reference. Preferably, the Main Taskand Subordinate Task(s) that would be developed for the ApplicationLayer would carry out the system and subsystem functionalities describedin the State Control Processes of FIG. 6G1A through 6G3B, and StateTransition Diagrams. In an illustrative embodiment, the Main Task wouldcarry out the basic object motion and velocity detection operationssupported within the 3D imaging volume by each of the coplanarillumination and imaging subsystems, and Subordinate Task would becalled to carry out the bar code reading operations the informationprocessing channels of those stations that are configured in their BarCode Reading State (Mode) of operation. Details of task development willreadily occur to those skilled in the art having the benefit of thepresent invention disclosure.

The Second Illustrative Embodiment of the Omni-Directional ImageCapturing and Processing Based Bar Code Symbol Reading System of thePresent Invention Employing Globally-Deployed Imaging-Based ObjectMotion/Velocity Detectors in the 3D Imaging Volume Thereof

As shown in FIG. 7A, a plurality of imaging-based object motion andvelocity “field of views” 120A, 120B and 120C are generated from aplurality of imaging-based motion/velocity detection subsystems 121installed in the system 10D, and operated during its ObjectMotion/Velocity Detection Mode. As these imaging-based object motion andvelocity “field of views” are not necessarily spatially co-extensive oroverlapping the coplanar illumination and imaging planes generatedwithin the 3D imaging volume by subsystem (i.e. station) 15 in thesystem, the FOVs of these object motion/velocity detecting subsystemswill need to use either ambient illumination or pulsed or continuouslyoperated LED or VLD illumination sources so as to illuminate their FOVsduring the Object Motion/Velocity Detection Mode of the system. Ideally,these illumination sources would produce IR illumination (e.g. in the850 nm range). The function of these globally deployed objectmotion/velocity detection subsystems is to enable automatic control ofillumination and/or exposure during the Bar Code Reading Mode of thesystem.

In FIG. 7A1, the system architecture of the omni-directional imagecapturing and processing based bar code symbol reading system 10D ofFIG. 7A is shown comprising: a complex of coplanar illuminating andlinear-imaging stations 15A through 15F constructed using the linearillumination arrays and image sensing arrays as described hereinabove;an multi-processor image processing subsystem 20 for supportingautomatic image processing based bar code symbol reading and opticalcharacter recognition (OCR) along each coplanar illumination and imagingplane within the system; a software-based object recognition subsystem21, for use in cooperation with the image processing subsystem 20, andautomatically recognizing objects (such as vegetables and fruit) at theretail POS while being imaged by the system; an electronic weight scale22 employing one or more load cells 23 positioned centrally below thesystem housing, for rapidly measuring the weight of objects positionedon the window aperture of the system for weighing, and generatingelectronic data representative of measured weight of the object; aninput/output subsystem 28 for interfacing with the image processingsubsystem, the electronic weight scale 22, RFID reader 26, credit-cardreader 27 and Electronic Article Surveillance (EAS) Subsystem 28(including EAS tag deactivation block integrated in system housing); awide-area wireless interface (WIFI) 31 including RF transceiver andantenna 31A for connecting to the TCP/IP layer of the Internet as wellas one or more image storing and processing RDBMS servers 33 (which canreceive images lifted by system for remote processing by the imagestoring and processing servers 33); a BlueTooth® RF 2-way communicationinterface 35 including RF transceivers and antennas 3A for connecting toBlue-tooth® enabled hand-held scanners, imagers, PDAs, portablecomputers 36 and the like, for control, management, application anddiagnostic purposes; and a global control subsystem 37 for controlling(i.e. orchestrating and managing) the operation of the coplanarillumination and imaging stations (i.e. subsystems), electronic weightscale 22, and other subsystems. As shown, each coplanar illumination andimaging subsystem 15′ transmits frames of image data to the imageprocessing subsystem 25, for state-dependent image processing and theresults of the image processing operations are transmitted to the hostsystem via the input/output subsystem 20. In FIG. 7A1, the bar codesymbol reading module employed along each channel of the multi-channelimage processing subsystem 20 can be realized using SwiftDecoder® ImageProcessing Based Bar Code Reading Software from Omniplanar Corporation,West Deptford, New Jersey, or any other suitable image processing basedbar code reading software. Also, the system provides full support for(i) dynamically and adaptively controlling system control parameters inthe digital image capture and processing system, as disclosed and taughtin Applicants' PCT Application Serial No. PCT/US2007/009763, as well as(ii) permitting modification and/or extension of system features andfunction, as disclosed and taught in PCT Application No. WO 2007/075519,supra.

As shown in FIGS. 7A2 and 7A3, each coplanar illumination and imagingstation 15 employed in the system of FIG. 7A comprises: an illuminationsubsystem 44 including a linear array of VLDs or LEDs 44A and 44B andassociated focusing and cylindrical beam shaping optics (i.e. planarillumination arrays PLIAs), for generating a planar illumination beam(PLIB) from the station; a linear image formation and detection (IFD)subsystem 40 having a camera controller interface (e.g. FPGA) 40A forinterfacing with the local control subsystem 50 and a high-resolutionlinear image sensing array 41 with optics providing a field of view(FOV) on the image sensing array that is coplanar with the PLIB producedby the linear illumination array 44A so as to form and detect lineardigital images of objects within the FOV of the system; a local controlsubsystem 50 for locally controlling the operation of subcomponentswithin the station, in response to control signals generated by globalcontrol subsystem 37 maintained at the system level, shown in FIG. 7A;an image capturing and buffering subsystem 48 for capturing lineardigital images with the linear image sensing array 41 and bufferingthese linear images in buffer memory so as to form 2D digital images fortransfer to image-processing subsystem 20 maintained at the systemlevel, as shown in FIG. 6B, and subsequent image processing according tobar code symbol decoding algorithms, OCR algorithms, and/or objectrecognition processes; a high-speed image capturing and processing basedmotion/velocity sensing subsystem 130 (similar to subsystem 49′) formeasuring the motion and velocity of objects in the 3D imaging volumeand supplying the motion and velocity data to the local controlsubsystem 50 for processing and automatic generation of control datathat is used to control the illumination and exposure parameters of thelinear image formation and detection system within the station. Detailsregarding the design and construction of planar illumination and imagingmodule (PLIIMs) can be found in Applicants' U.S. Pat. No. 7,028,899 B2incorporated herein by reference.

As shown in FIG. 7A3, the high-speed image capturing and processingbased motion/velocity sensing subsystem 130 comprises: an area-typeimage acquisition subsystem 131 with an area-type image sensing array132 and optics 133 for generating a field of view (FOV) that ispreferably spatially coextensive with the longer dimensions of the FOVof the linear image formation and detection subsystem 40; an (IR)illumination area-type illumination subsystem 134 having an a pair of IRillumination arrays 134A and 134B; and an embedded digital signalprocessing (DSP) image processor 135 for automatically processing 2Dimages captured by the digital image acquisition subsystem 131. The DSPimage processor 135 processes captured images so as to automaticallyabstract, in real-time, motion and velocity data from the processedimages and provide this motion and velocity data to the global controlsubsystem 37, or alternatively to local control subsystem 40 of eachstation 15, for the processing and automatic generation of control datathat is used to control the illumination and/or exposure parameters ofthe linear image formation and detection system within the station.

In the illustrative embodiment shown in FIGS. 7A3 and 7A4, each imagecapturing and processing based motion/velocity sensing subsystem 130continuously and automatically computes the motion and velocity ofobjects passing through the planar FOV of the station, and uses thisdata to generate control signals that set the frequency of the clocksignal used to read out data from the linear image sensing array 41employed in the linear image formation and detection subsystem of thesystem

As shown in FIG. 7A3, the area-type LED or VLD based illumination array132 and the area-type image sensing array 131 cooperate to producedigital images of IR-illuminated objects passing through at least at aportion of the FOV of the linear image formation and detection subsystem40. Then, DSP-based image processor (e.g. ASICs) process captured imagesusing cross-correlation functions to compute (i.e. measure) motion andvelocity regarding object(s) within the FOV of the linear imageformation and detection subsystem. This motion and velocity data is thenprovided to the global subsystem controller 37 so that it can generate(i.e. compute) control data for controlling the frequency of the clocksignal used in reading data out of the linear image sensing arrays ofthe image formation and detection subsystems 40 in the stations of thesystem. Alternatively, this motion and velocity data can be sent to thelocal control subsystems for local computation of control data forcontrolling the illumination and/or exposure parameters employed in thestation. An algorithm for computing such control data, based on sensed2D images of objects moving through (at least a portion of) the FOV ofthe linear image formation and detection subsystem, is described in FIG.7A4 and the Specification set forth hereinabove. While the systemembodiments of FIGS. 7A3 and 7A4 illustrate controlling the clockfrequency in the image formation and detection subsystem, it isunderstood that other camera parameters, relating to exposure and/orillumination, can be controlled in accordance with the principles of thepresent invention.

In general, there are two different methods for realizing non-contactimaging-based velocity sensors for use in detecting the motion andvelocity of objects passing through the 3D imaging volume of the systemof the present invention, depicted in FIG. 7B, namely: (1) forming anddetecting images of objects using incoherent illumination produced froman array of LEDs or like illumination source (i.e. incoherentPulse-Doppler LIDAR); and (2) forming and detecting images of objectsusing coherent illumination produced from an array of VLDs or otherlaser illumination sources (i.e. coherent Pulse-Doppler LIDAR).

According to the first method, a beam of incoherent light is generatedby an array of LEDs 134 emitting at a particular band of wavelengths,and then this illumination is directed into the field of view of theimage acquisition subsystem 131 of the image-based objectmotion/velocity sensor 130 shown in FIG. 7A3 and 7A4. According to thismethod, the pairs of 1D or 2D images of objects illuminated by suchillumination will be formed by the light absorptive or reflectiveproperties on the surface of the object, while moving through the 3Dimaging volume of the system. For objects having poor light reflectivecharacteristics at the illumination wavelength of the subsystem,low-contrast, poor quality images will be detected by the imageacquisition subsystem 131 of the object motion/velocity sensor 130making it difficult for the DSP processor 135 and its cross-correlationfunctions to abstract motion and velocity measurements. Thus, when usingthe first method, there is the tendency to illuminate objects usingillumination in the visible band, because most objects passing throughthe 3D imaging volume at the POS environment reflects light energy quitewell at such optical wavelengths. The challenge, however, when usingvisible illumination during the Object Motion/Velocity Detection Mode ofthe system is that it is undesirable to produce visible energy duringsuch modes of operation, as it will disturb the system operator andnearby consumers present at the POS station. This creates an incentiveto use an array of IR LEDs to produce a beam of wide-area illuminationat IR wavelengths (e.g. 850 nm) during the Object Motion/VelocityDetection Mode of operation. However, in some applications, the use ofwide-area IR illumination from an array of IR LEDs may not be feasibledue to significant levels of noise present in the IR band. In suchinstances, it might be helpful to look the second method of forming anddetecting “speckle-noise” images using highly coherent illumination.

According to the second method, a beam of coherent light is generated byan array of VLDs 134 emitting at a particular band of wavelengths (e.g.850 nm), and then this illumination is directed into the field of viewof the optics employed in the image acquisition subsystem 131 of theobject motion/velocity sensor 130, shown in FIG. 7A3. According to thismethod, the pairs of 1D or 2D “speckle-noise” images of objects(illuminated by such highly coherent illumination) will be formed by theIR absorptive or scattering properties of the surface of the object,while the object is moving through the 3D imaging volume of the system.Formation of speckle-pattern noise within the FOV of the motion/velocitysensor is a well known phenomena of physics, wherein laser lightilluminating a rough surface naturally generates speckle-pattern noisein the space around the object surface, and detected images of thetarget object will thus have speckle-pattern noise. Then, during imageprocessing in the DSP processor, speckle-processing algorithms can beused to appraise the best cross-correlation function for object velocitymeasurement. Such speckle-processing algorithms can be based on binarycorrelation or on Fast Fourier Transform (FFT) analysis of imagesacquired by the image-based motion/velocity sensor 130. Using thisapproach, a coherent Pulse-Doppler LIDAR motion/velocity sensor can beconstructed, having reduced optical complexity and very low cost. Theworking distance of this kind of non-contact object velocity sensor canbe made to extend within the 3D imaging volume of the system by (i)placing suitable light dispersive optics placed before the IR laserillumination source to fill the FOV of the image sensor, and (ii)placing collimating optics placed before the image sensing array of thesensor. Details regarding such a coherent IR speckle-basedmotion/velocity sensor are disclosed in the IEEE paper entitled“Instrumentation and Measurement”, published in IEEE Transactions onVolume 53, Issue 1, on February 2004, at Page(s) 51-57, incorporatedherein by reference.

The Third Illustrative Embodiment of the Omni-Directional ImageCapturing and Processing Based Bar Code Symbol Reading System of thePresent Invention Employing Globally-Deployed IR Pulse-Doppler LIDARBased Object Motion/Velocity Detectors in The 3D Imaging Volume Thereof

In FIG. 7B, a second alternative embodiment of the omni-directionalimage capturing and processing based bar code symbol reading system ofthe present invention 10E is shown removed from its POS environment,with one coplanar illumination and imaging plane being projected throughan aperture in its imaging window protection plate 17. In thisillustrative embodiment, each coplanar illumination and imaging planeprojected through the 3D imaging volume 16 of the system has a pluralityof IR Pulse-Doppler LIDAR based object motion/velocity sensing beams (A,B, C) that are spatially co-incident therewith, for sensing in real-timethe motion and velocity of objects passing therethrough during systemoperation. As shown in greater detail, the of IR Pulse-Doppler LIDARbased object motion/velocity sensing beams (A, B, C) are generated froma plurality of IR Pulse-Doppler LIDAR motion/velocity detectionsubsystems 140, which can be realized using a plurality of IR (Coherentor Incoherent) Pulse-Doppler LIDAR motion/velocity sensing chips mountedalong the illumination array provided at each coplanar illumination andimaging station 15 in the system. In the illustrative embodiments ofFIG. 7B, three such IR Pulse-Doppler LIDAR motion/velocity sensing chips(e.g. Philips PLN2020 Twin-Eye 850 nm IR Laser-Based Motion/VelocitySensor System in a Package (SIP)) are employed in each station in thesystem. Details regarding this subsystem are described in FIGS. 8C, 8Dand 8E and corresponding portions of the present patent Specification.

As shown in FIG. 7B1, the omni-directional image capturing andprocessing based bar code symbol reading system 10E comprises: complexof coplanar illuminating and linear imaging stations 15A through 15Aconstructed using the linear illumination arrays and image sensingarrays described above; a multi-processor image processing subsystem 20for supporting automatic image processing based bar code symbol readingand optical character recognition (OCR) along each coplanar illuminationand imaging plane within the system; a software-based object recognitionsubsystem 21, for use in cooperation with the image processing subsystem20, and automatically recognizing objects (such as vegetables and fruit)at the retail POS while being imaged by the system; an electronic weightscale 22 employing one or more load cells 23 positioned centrally belowthe system housing, for rapidly measuring the weight of objectspositioned on the window aperture of the system for weighing, andgenerating electronic data representative of measured weight of theobject; an input/output subsystem 28 for interfacing with the imageprocessing subsystem, the electronic weight scale 22, RFID reader 26,credit-card reader 27 and Electronic Article Surveillance (EAS)Subsystem 28 (including EAS tag deactivation block integrated in systemhousing); a wide-area wireless interface (WIFI) 31 including RFtransceiver and antenna 31A for connecting to the TCP/IP layer of theInternet as well as one or more image storing and processing RDBMSservers 33 (which can receive images lifted by system for remoteprocessing by the image storing and processing servers 33); a BlueTooth®RF 2-way communication interface 35 including RF transceivers andantennas 3A for connecting to Blue-tooth® enabled hand-held scanners,imagers, PDAs, portable computers 36 and the like, for control,management, application and diagnostic purposes; and a global controlsubsystem 37 for controlling (i.e. orchestrating and managing) theoperation of the coplanar illumination and imaging stations (i.e.subsystems), electronic weight scale 22, and other subsystems. As shown,each coplanar illumination and imaging subsystem 15 transmits frames ofimage data to the image processing subsystem 25, for state-dependentimage processing and the results of the image processing operations aretransmitted to the host system via the input/output subsystem 20. InFIG. 8B1, the bar code symbol reading module employed along each channelof the multi-channel image processing subsystem 20 can be realized usingSwiftDecoder® Image Processing Based Bar Code Reading Software fromOmniplanar Corporation, West Deptford, N.J., or any other suitable imageprocessing based bar code reading software. Also, the system providesfull support for (i) dynamically and adaptively controlling systemcontrol parameters in the digital image capture and processing system,as disclosed and taught in Applicants' PCT Application Serial No.PCT/US2007/009763, as well as (ii) permitting modification and/orextension of system features and function, as disclosed and taught inPCT Application No. WO 2007/075519, supra.

As shown in FIG. 7B2, each coplanar illumination and imaging stations 15employed in the system embodiment of FIG. 7B1, comprises: anillumination subsystem 44 including planar illumination arrays (PLIA)44A and 44B; a linear image formation and detection subsystem 40including linear image sensing array 41 and optics 42 providing a fieldof view (FOV) on the image sensing array; an image capturing andbuffering subsystem 48; and a local control subsystem 50.

In the illustrative embodiment of FIG. 7C, each globally deployed IRPulse-Doppler LIDAR based object motion/velocity sensing subsystem 140can be realized using a high-speed IR Pulse-Doppler LIDAR basedmotion/velocity sensor, as shown in FIGS. 6D1′, 6D2′, and 6E′ anddescribed in great technical detail above. The purpose of this sensor140 is to (i) detect whether or not an object is present within the FOVat any instant in time, and (ii) detect the motion and velocity ofobjects passing through the FOV of the linear image sensing array, forultimately controlling camera parameters in real-time, including theclock frequency of the linear image sensing array. FIG. 7D shows ingreater detail the IR Pulse-Doppler LIDAR based object motion/velocitydetection subsystem 140 and how it cooperates with the local controlsubsystem, the planar illumination array (PLIA), and the linear imageformation and detection subsystem.

Having described two alternative system embodiments employingglobally-deployed object motion/velocity sensing, as shown in FIGS. 7Athrough 7A4, and 7B through 7E, it is appropriate at this juncture tonow describe various system control methods that can be used inconnection with these system embodiments.

As shown in FIG. 7F, a state transition diagram is provided for theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 7A and 7B, running the system controlprogram described in flow chart of FIG. 7, with globally-controlledobject motion/velocity detection provided in each coplanar illuminationand imaging subsystem of the system, as illustrated in FIGS. 7A and 7B.The flow chart of FIG. 7 describes the operations (i.e. tasks) that areautomatically performed during the state control process of FIG. 7F,which is carried out within the omni-directional image capturing andprocessing based bar code symbol reading system described in FIGS. 7Aand 7B.

At Step A in FIG. 7, upon powering up the Omni-Directional Imagecapturing and processing based Bar Code Symbol Reading System (“System”)10E, and/or after each successful read of a bar code symbol thereby, theglobal control subsystem 37 initializes the system by pre-configuringeach Coplanar Illumination and Imaging Station 15 employed therein inits Object Motion/Velocity Detection State which is essentially a“stand-by” sort of state because the globally-deployed objectmotion/velocity sensor 140 has been assigned the task of carrying outthis function in the system.

As indicated at Step B in FIG. 7, at each Coplanar Illumination andImaging Station currently configured in its Object Motion/VelocityDetection State, the object motion/velocity detection subsystem 140automatically detects the motion and velocity of an object being passedthrough the 3D imaging volume of the station and generate datarepresentative thereof. From this data, the local control subsystemsgenerate control data for use in controlling the exposure and/orillumination processes at coplanar illumination and imaging stations(e.g. the frequency of the clock signal used in the IFD subsystem).

As indicated at Step C in FIG. 7, for each Coplanar Illumination andImaging Station that automatically detects an object moving through orwithin its Object Motion/Velocity Detection Field with the help ofglobally deployed motion/velocity sensors 140, and in response tocontrol data from the global control subsystem 37, the local controlsubsystem 50 automatically configures the Coplanar Illumination andImaging Station into its Imaging-Based Bar Code Reading Mode (State).

During the Imaging-Based Bar Code Reading Mode (State), the illuminationarrays of the illumination subsystem 44 are preferably driven at fullpower. Optionally, in some applications, the object motion/velocitysensing subsystem may be permitted to simultaneously collect (during theImaging-Based Bar Code Reading State) updated object motion and velocitydata for use in dynamically controlling the exposure and/or illuminationparameters of the IFD Subsystem.

As indicated at Step D in FIG. 7, from each Coplanar Illumination andImaging Station currently configured in its Imaging-Based Bar CodeSymbol Reading State, the station automatically illuminates the detectedobject, with laser or VLD illumination (as the case may be), andcaptures and buffers digital 1D images thereof, and transmits thesereconstructed 2D images to the global multi-processor image processingsubsystem 20 for processing these buffered images so as to read a 1D or2D bar code symbol represented in the images.

As indicated at Step E of FIG. 7, upon the 1D or 2D bar code symbolbeing successfully read by at least one of the Coplanar Illumination andImaging Stations in the System, the image processing subsystemautomatically generates symbol character data representative of the readbar code symbol, transmits the symbol character data to the input/outputsubsystem, and the global control subsystem reconfigures each CoplanarIllumination and Imaging Station back into its Object Motion/VelocityDetection State and returns to Step B, so that the system can resumeautomatic detection of object motion and velocity within the 3D imagingvolume of the system.

As indicated at Step F in FIG. 7, upon failure to read at least 1D or 2Dbar code symbol within a predetermined time period (from the time anobject has been detected within the 3D imaging volume), the localcontrol subsystem (under global control) reconfigures the coplanarillumination and imaging station to its Object Motion and VelocityDetection State (i.e. Stand-By State) at Step B, to allow the system toresume collection and updating of object motion and velocity data (andderive control data for exposure and/or illumination control).

FIG. 7H describes an exemplary embodiment of a computing and memoryarchitecture platform that can be used to implement the omni-directionalimage capturing and processing based bar code symbol reading systemdescribed in FIGS. 7A and 7B. As shown, this hardware computing andmemory platform can be realized on a single PC board, along with theelectro-optics associated with the coplanar illumination and imagingstations and other subsystems described in FIGS. 8G1A and 8G1B. Asshown, the hardware platform comprises: at least one, but preferablymultiple high speed dual core microprocessors, to provide amulti-processor architecture having high bandwidth video-interfaces andvideo memory and processing support; an FPGA (e.g. Spartan 3) formanaging the digital image streams supplied by the plurality of digitalimage capturing and buffering channels, each of which is driven by acoplanar illumination and imaging station (e.g. linear CCD or CMOS imagesensing array, image formation optics, etc) in the system; a robustmulti-tier memory architecture including DRAM, Flash Memory, SRAM andeven a hard-drive persistence memory in some applications; arrays ofVLDs and/or LEDs, associated beam shaping and collimating/focusingoptics; and analog and digital circuitry for realizing the illuminationsubsystem; interface board with microprocessors and connectors; powersupply and distribution circuitry; as well as circuitry for implementingthe others subsystems employed in the system.

FIG. 8I 7I describes a three-tier software architecture that can runupon the computing and memory architecture platform of FIG. 8H 7H, so asto implement the functionalities of the omni-directional image capturingand processing based bar code symbol reading system systems described

FIGS. 8A and 8B 7A and 7B. Details regarding the foundations of thisthree-tier architecture can be found in Applicants' copending U.S.patent Ser. No. 11/408,268, incorporated herein by reference.Preferably, the Main Task and Subordinate Task(s) that would bedeveloped for the Application Layer would carry out the system andsubsystem functionalities described in the State Control Processes ofFIG. 8 7G, and State Transition Diagram of FIG. 8 7F. In an illustrativeembodiment, the Main Task would carry out the basic object motion andvelocity detection operations supported within the 3D imaging volume byeach of the coplanar illumination and imaging subsystems, andSubordinate Task would be called to carry out the bar code readingoperations the information processing channels of those stations thatare configured in their Bar Code Reading State (Mode) of operation.Details of task development will readily occur to those skilled in theart having the benefit of the present invention disclosure.

The Third Illustrative Embodiment of the Omni-Directional ImageCapturing and Processing Based Bar Code Symbol Reading System of thePresent Invention

FIG. 8A shows a fourth illustrative embodiment of the omni-directionalimage capturing and processing based bar code symbol reading system ofthe present invention 150 installed in the countertop surface of aretail POS station. As shown, the omni-directional image capturing andprocessing based bar code symbol reading system 150 comprises bothvertical and horizontal housing sections, each provided with coplanarillumination and imaging stations for aggressively supporting both“pass-through” as well as “presentation” modes of bar code imagecapture.

As shown in greater detail in FIG. 8B, the omni-directional imagecapturing and processing based bar code symbol reading system 150comprises: a horizontal section 10 (e.g. 10A, 10B, . . . 10E) forprojecting a first complex of coplanar illumination and imaging planes55 from its horizontal imaging window; and a vertical section 160 thatprojects (i) one horizontally-extending coplanar illumination andimaging plane 161 and (ii) two vertically-extending spaced-apartcoplanar illumination and imaging planes 162A and 162B from itsapertures 164 formed in a protection plate 165 releasably mounted oververtical imaging window 166, into the 3D imaging volume of the system,enabling to aggressive support for both “pass-through” as well as“presentation” modes of bar code image capture. The primary functions ofeach coplanar laser illumination and imaging station is to generate andproject coplanar illumination and imaging planes through the imagingwindow and apertures into the 3D imaging volume of the system, andcapture digital linear (1D) digital images along the field of view (FOV)of these illumination and linear imaging planes. These captured linearimages are then buffered and decode-processed using linear (1D) typeimage capturing and processing based bar code reading algorithms, or canbe assembled together to reconstruct 2D images for decode-processingusing 1D/2D image processing based bar code reading techniques.

In general, each coplanar illumination and imaging station employed inthe system of FIG. 9B can be realized as a linear array of VLDs or LEDsand associated focusing and cylindrical beam shaping optics (i.e. planarillumination arrays PLIAs) are used to generate a substantially planarillumination beam (PLIB) from each station, that is coplanar with thefield of view of the linear (1D) image sensing array employed in thestation. Any of the station designs described hereinabove can be used toimplement this illustrative system embodiment. Details regarding thedesign and construction of planar laser illumination and imaging module(PLIIMs) can be found in Applicants' U.S. Pat. No. 7,028,899 B2incorporated herein by reference.

In FIG. 8C, the system architecture of the omni-directional imagecapturing and processing based bar code symbol reading system of FIG. 8Bis shown comprising: a complex of coplanar illuminating and linearimaging stations 15 constructed using LED or VLD based linearillumination arrays and image sensing arrays, as described hereinabove;an multi-channel multi-processor image processing subsystem 20 forsupporting automatic object motion/velocity detection and intelligentautomatic laser illumination control within the 3D imaging volume, aswell as automatic image processing based bar code reading along eachcoplanar illumination and imaging plane within the system; asoftware-based object recognition subsystem 21, for use in cooperationwith the image processing subsystem 20, and automatically recognizingobjects (such as vegetables and fruit) at the retail POS while beingimaged by the system; an electronic weight scale 22 employing one ormore load cells 23 positioned centrally below the system housing, forrapidly measuring the weight of objects positioned on the windowaperture of the system for weighing, and generating electronic datarepresentative of measured weight of the object; an input/outputsubsystem 28 for interfacing with the image processing subsystem, theelectronic weight scale 22, RFID reader 26, credit-card reader 27 andElectronic Article Surveillance (EAS) Subsystem 28 (including EAS tagdeactivation block integrated in system housing)s; a wide-area wirelessinterface (WIFI) 31 including RF transceiver and antenna 31A forconnecting to the TCP/IP layer of the Internet as well as one or moreimage storing and processing RDBMS servers 33 (which can receive imageslifted by system for remote processing by the image storing andprocessing servers 33); a BlueTooth® RF 2-way communication interface 35including RF transceivers and antennas 3A for connecting to Blue-tooth®enabled hand-held scanners, imagers, PDAs, portable computers 36 and thelike, for control, management, application and diagnostic purposes; anda global control subsystem 37 for controlling (i.e. orchestrating andmanaging) the operation of the coplanar illumination and imagingstations (i.e. subsystems), electronic weight scale 22, and othersubsystems. As shown, each coplanar illumination and imaging subsystem15′ transmits frames of image data to the image processing subsystem 25,for state-dependent image processing and the results of the imageprocessing operations are transmitted to the host system via theinput/output subsystem 20.

As shown in FIGS. 8D and 8E, each coplanar illumination and imagingstation 15 employed in the system of FIGS. 8B and 8C comprises: anillumination subsystem 44 including a linear array of VLDs or LEDs andassociated focusing and cylindrical beam shaping optics (i.e. planarillumination arrays PLIAs), for generating a planar illumination beam(PLIB) from the station; a linear image formation and detection (IFD)subsystem 40 having a camera controller interface (e.g. FPGA) forinterfacing with the local control subsystem 50 and a high-resolutionlinear image sensing array 41 with optics 42 providing a field of view(FOV) on the image sensing array that is coplanar with the PLIB producedby the linear illumination array 41, so as to form and detect lineardigital images of objects within the FOV of the system; a local controlsubsystem 50 for locally controlling the operation of subcomponentswithin the station, in response to control signals generated by globalcontrol subsystem 37 maintained at the system level, shown in FIG. 8B;an image capturing and buffering subsystem 48 for capturing lineardigital images with the linear image sensing array 41 and bufferingthese linear images in buffer memory so as to form 2D digital images fortransfer to image-processing subsystem 20 maintained at the systemlevel, as shown in FIG. 8B, and subsequent image processing according tobar code symbol decoding algorithms, OCR algorithms, and/or objectrecognition processes; a high-speed image capturing and processing basedmotion/velocity sensing subsystem 49 for producing motion and velocitydata for supply to the local control subsystem 50 for processing andautomatic generation of control data that is used to control theillumination and exposure parameters of the linear image formation anddetection system within the station. Details regarding the design andconstruction of planar illumination and imaging module (PLIIMs) can befound in Applicants' U.S. Pat. No. 7,028,899 B2 incorporated herein byreference.

As shown in FIGS. 8D and 8E, the high-speed motion/velocity detectionsubsystem 49 can be realized any of the motion/velocity detectiontechniques detailed hereinabove so as to provide real-time motion andvelocity data to the local control subsystem 50 for processing andautomatic generation of control data that is used to control theillumination and exposure parameters of the linear image formation anddetection system within the station. Alternatively, motion/velocitydetection subsystem 49 can be deployed outside of illumination andimaging station, as positioned globally as shown in FIGS. 8A and 8B.

As shown in FIG. 8F1, a state transition diagram is provided for theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 8B and 8C, running the system controlprogram generally described in flow charts of FIGS. 6G1A and 6G1B, withlocally-controlled imaging-based object motion/velocity detectionprovided in each coplanar illumination and imaging subsystem of thesystem, as illustrated in FIG. 8B. The flow chart of FIGS. 6G1A and 6G1Bgenerally describes the operations (i.e. tasks) that are automaticallyperformed during the state control process of FIG. 8F1, which is carriedout within the omni-directional image capturing and processing based barcode symbol reading system described in FIGS. 8B and 8C.

As shown in FIG. 8F2, a state transition diagram is provided for theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 8B and 8C, running the system controlprogram generally described in flow charts of FIGS. 6G2A and 6G2B,employing locally-controlled object motion/velocity detection in eachcoplanar illumination and imaging subsystem of the system, withglobally-controlled over-driving of nearest-neighboring stations. Theflow chart of FIGS. 6G2A and 6G2B generally describes the operations(i.e. tasks) that are automatically performed during the state controlprocess of FIG. 8F2, which is carried out within the omni-directionalimage capturing and processing based bar code symbol reading systemdescribed in FIGS. 9A and 9B 8A and 8B.

As shown in FIG. 8F3, a state transition diagram is provided for theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 8B and 8C, running the system controlprogram generally described in flow charts of FIGS. 6G3A and 6G3B,employing locally-controlled object motion/velocity detection in eachcoplanar illumination and imaging subsystem of the system, withglobally-controlled over-driving of all-neighboring stations. The flowchart of FIGS. 6G3A and 6G3B describes the operations (i.e. tasks) thatare automatically performed during the state control process of FIG.8F3, which is carried out within the omni-directional image capturingand processing based bar code symbol reading system described in FIGS.8B and 8C.

FIG. 8G describes an exemplary embodiment of a computing and memoryarchitecture platform that can be used to implement the omni-directionalimage capturing and processing based bar code symbol reading systemdescribed in FIGS. 8B and 8C. As shown, this hardware computing andmemory platform can be realized on a single PC board, along with theelectro-optics associated with the coplanar illumination and imagingstations and other subsystems generally described in FIGS. 6G1A through6G3B. As shown, the hardware platform comprises: at least one, butpreferably multiple high speed dual core microprocessors, to provide amulti-processor architecture having high bandwidth video-interfaces andvideo memory and processing support; an FPGA (e.g. Spartan 3) formanaging the digital image streams supplied by the plurality of digitalimage capturing and buffering channels, each of which is driven by acoplanar illumination and imaging station (e.g. linear CCD or CMOS imagesensing array, image formation optics, etc) in the system; a robustmulti-tier memory architecture including DRAM, Flash Memory, SRAM andeven a hard-drive persistence memory in some applications; arrays ofVLDs and/or LEDs, associated beam shaping and collimating/focusingoptics; and analog and digital circuitry for realizing the illuminationsubsystem; interface board with microprocessors and connectors; powersupply and distribution circuitry; as well as circuitry for implementingthe others subsystems employed in the system.

FIG. 8H describes a three-tier software architecture that can run uponthe computing and memory architecture platform of FIG. 8G, so as toimplement the functionalities of the omni-directional image capturingand processing based bar code symbol reading system described FIGS. 8Band 9C 8C. Details regarding the foundations of this three-tierarchitecture can be found in Applicants' copending U.S. application Ser.No. 11/408,268, incorporated herein by reference. Preferably, the MainTask and Subordinate Task(s) that would be developed for the ApplicationLayer would carry out the system and subsystem functionalities generallydescribed in the State Control Processes of FIGS. 6G1A through 6G3B, andState Transition Diagrams of FIGS. 8F1 through 8F3. In an illustrativeembodiment, the Main Task would carry out the basic object motion andvelocity detection operations supported within the 3D imaging volume byeach of the coplanar illumination and imaging subsystems, andSubordinate Task would be called to carry out the bar code readingoperations the information processing channels of those stations thatare configured in their Bar Code Reading State (Mode) of operation.Details of task development will readily occur to those skilled in theart having the benefit of the present invention disclosure.

The Fourth Illustrative Embodiment of the Omni-Directional ImageCapturing and Processing Based Bar Code Symbol Reading System of thePresent Invention

FIG. 9A shows a fifth illustrative embodiment of the omni-directionalimage capturing and processing based bar code symbol reading system ofthe present invention 170 installed in the countertop surface of aretail POS station. As shown, the omni-directional image capturing andprocessing based bar code symbol reading system comprises both verticaland horizontal housing sections, each provided with coplanarillumination and imaging stations for aggressively supporting both“pass-through” as well as “presentation” modes of bar code imagecapture.

As shown in greater detail in FIG. 9B, the omni-directional imagecapturing and processing based bar code symbol reading system 170comprises: a horizontal section 10 (e.g. 10A, 10B, . . . 10E) forprojecting a first complex of coplanar illumination and imaging planesfrom its horizontal imaging window; and a vertical section 175 thatprojects three vertically-extending spaced-apart coplanar illuminationand imaging planes 55 from its vertical imaging window 176 into the 3Dimaging volume 16 of the system so as to aggressively support a“pass-through” mode of bar code image capture. The primary functions ofeach coplanar illumination and imaging station 15 is to generate andproject coplanar illumination and imaging planes through the imagingwindow and apertures into the 3D imaging volume of the system, andcapture digital linear (1D) digital images along the field of view (FOV)of these illumination and linear imaging planes. These captured linearimages are then buffered and decode-processed using linear (1D) typeimage capturing and processing based bar code reading algorithms, or canbe assembled together to reconstruct 2D images for decode-processingusing 1D/2D image processing based bar code reading techniques.

In general, each coplanar illumination and imaging station 15 employedin the system of FIG. 9B (in both horizontal and vertical sections) canbe realized as a linear array of VLDs or LEDs and associated focusingand cylindrical beam shaping optics (i.e. planar illumination arraysPLIAs) used to generate a substantially planar illumination beam (PLIB)from each station, that is coplanar with the field of view of the linear(1D) image sensing array employed in the station. Details regarding thedesign and construction of planar illumination and imaging module(PLIIMs) can be found in Applicants' U.S. Pat. No. 7,028,899 B2incorporated herein by reference.

In FIG. 9C, the system architecture of the omni-directional imagecapturing and processing based bar code symbol reading system 170 ofFIG. 9B is shown comprising: a complex of coplanar illuminating andlinear imaging stations 15A through 151, constructed using LED or VLDbased linear illumination arrays and image sensing arrays, as describedhereinabove; an multi-channel multi-processor image processing subsystem20 for supporting automatic image processing based bar code readingalong each coplanar illumination and imaging plane within the system; asoftware-based object recognition subsystem 21, for use in cooperationwith the image processing subsystem 20, and automatically recognizingobjects (such as vegetables and fruit) at the retail POS while beingimaged by the system; an electronic weight scale 22 employing one ormore load cells 23 positioned centrally below the system housing, forrapidly measuring the weight of objects positioned on the windowaperture of the system for weighing, and generating electronic datarepresentative of measured weight of the object; an input/outputsubsystem 28 for interfacing with the image processing subsystem, theelectronic weight scale 22, RFID reader 26, credit-card reader 27 andElectronic Article Surveillance (EAS) Subsystem 28 (including EAS tagdeactivation block integrated in system housing)s; a wide-area wirelessinterface (WIFI) 31 including RF transceiver and antenna 31A forconnecting to the TCP/IP layer of the Internet as well as one or moreimage storing and processing RDBMS servers 33 (which can receive imageslifted by system for remote processing by the image storing andprocessing servers 33); a BlueTooth® RF 2-way communication interface 35including RF transceivers and antennas 3A for connecting to Blue-tooth®enabled hand-held scanners, imagers, PDAs, portable computers 36 and thelike, for control, management, application and diagnostic purposes; anda global control subsystem 37 for controlling (i.e. orchestrating andmanaging) the operation of the coplanar illumination and imagingstations (i.e. subsystems), electronic weight scale 22, and othersubsystems. As shown, each coplanar illumination and imaging subsystem15′ transmits frames of image data to the image processing subsystem 25,for state-dependent image processing and the results of the imageprocessing operations are transmitted to the host system via theinput/output subsystem 20.

As shown in FIGS. 9D and 9E, each coplanar illumination and imagingstation employed in the system of FIGS. 9B and 9C comprises: anillumination subsystem 44 including a linear array of VLDs or LEDs andassociated focusing and cylindrical beam shaping optics (i.e. planarillumination arrays PLIAs), for generating a planar illumination beam(PLIB) from the station 15; a linear image formation and detection (IFD)subsystem 40 having a camera controller interface (e.g. FPGA) 40A forinterfacing with local control subsystem 50, and a high-resolutionlinear image sensing array 41 with optics 42 providing a field of view(FOV) on the image sensing array that is coplanar with the PLIB producedby the linear illumination array 41 so as to form and detect lineardigital images of objects within the FOV of the system; a local controlsubsystem 50 for locally controlling the operation of subcomponentswithin the station, in response to control signals generated by globalcontrol subsystem 37 maintained at the system level, shown in FIG. 9B;an image capturing and buffering subsystem 48 for capturing lineardigital images with the linear image sensing array 41 and bufferingthese linear images in buffer memory so as to form 2D digital images fortransfer to image-processing subsystem 20 maintained at the systemlevel, as shown in FIG. 9B, and subsequent image processing according tobar code symbol decoding algorithms, OCR algorithms, and/or objectrecognition processes; a high-speed image capturing and processing basedmotion/velocity sensing subsystem 49 for producing motion and velocitydata for supply to the local control subsystem 50 for processing andautomatic generation of control data that is used to control theillumination and exposure parameters of the linear image formation anddetection system within the station. Details regarding the design andconstruction of planar illumination and imaging module (PLIIMs) can befound in Applicants' U.S. Pat. No. 7,028,899 B2 incorporated herein byreference.

As shown in FIGS. 9D and 9E, the high-speed motion/velocity detectionsubsystem 49 can be realized using any of the techniques describedherein so as to generate, in real-time, motion and velocity data forsupply to the local control subsystem 50 for processing and automaticgeneration of control data that is used to control the illumination andexposure parameters of the linear image formation and detectionsubsystem 40 within the station. Alternatively, motion/velocitydetection subsystem 49 can be deployed outside of illumination andimaging station, and positioned globally as shown in FIGS. 9A and 9B.

As shown in FIG. 9F1, a state transition diagram is provided for theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 9B and 9C, running the system controlprogram generally described in flow charts of FIGS. 6G1A and 6G1B, withlocally-controlled imaging-based object motion/velocity detectionprovided in each coplanar illumination and imaging subsystem of thesystem, as illustrated in FIG. 9B. The flow chart of FIGS. 6G1A and 6G1Bgenerally describes the operations (i.e. tasks) that are automaticallyperformed during the state control process of FIG. 9F1, which is carriedout within the omni-directional image capturing and processing based barcode symbol reading system described in FIGS. 10B and 10C 9B and 9C.

As shown in FIG. 9F2, a state transition diagram is provided for theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 9B and 9C, running the system controlprogram generally described in flow charts of FIGS. 6G2A and 6G2B,employing locally-controlled object motion/velocity detection in eachcoplanar illumination and imaging subsystem of the system, withglobally-controlled over-driving of nearest-neighboring stations. Theflow chart of FIGS. 6G2A and 6G2B generally describes the operations(i.e. tasks) that are automatically performed during the state controlprocess of FIG. 10F2 9F2, which is carried out within theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 9A and 9B.

As shown in FIG. 9F3, a state transition diagram is provided for theomni-directional image capturing and processing based bar code symbolreading system described in FIGS. 9B and 9C, running the system controlprogram generally described in flow charts of FIGS. 6G3A and 6G3B,employing locally-controlled object motion/velocity detection in eachcoplanar illumination and imaging subsystem of the system, withglobally-controlled over-driving of all-neighboring stations. The flowchart of FIGS. 6G3A and 6G3B generally describes the operations (i.e.tasks) that are automatically performed during the state control processof FIG. 10F3 9F3, which is carried out within the omni-directional imagecapturing and processing based bar code symbol reading system describedin FIGS. 9B and 9C.

FIG. 9G describes an exemplary embodiment of a computing and memoryarchitecture platform that can be used to implement the omni-directionalimage capturing and processing based bar code symbol reading systemdescribed in FIGS. 9B and 9C. As shown, this hardware computing andmemory platform can be realized on a single PC board, along with theelectro-optics associated with the coplanar or coextensive-areaillumination and imaging stations and other subsystems described inFIGS. 9G1A through 9G3B hereinabove. As shown, the hardware platformcomprises: at least one, but preferably multiple high speed dual coremicroprocessors, to provide a multi-processor architecture having highbandwidth video-interfaces and video memory and processing support; anFPGA (e.g. Spartan 3) for managing the digital image streams supplied bythe plurality of digital image capturing and buffering channels, each ofwhich is driven by a coplanar or coextensive-area illumination andimaging station (e.g. linear CCD or CMOS image sensing array, imageformation optics, etc) in the system; a robust multi-tier memoryarchitecture including DRAM, Flash Memory, SRAM and even a hard-drivepersistence memory in some applications; arrays of VLDs and/or LEDs,associated beam shaping and collimating/focusing optics; and analog anddigital circuitry for realizing the illumination subsystem; interfaceboard with microprocessors and connectors; power supply and distributioncircuitry; as well as circuitry for implementing the others subsystemsemployed in the system.

FIG. 9H describes a three-tier software architecture that can run uponthe computing and memory architecture platform of FIG. 9G, so as toimplement the functionalities of the omni-directional image capturingand processing based bar code symbol reading system described FIGS. 9Band 9C. Details regarding the foundations of this three-tierarchitecture can be found in Applicants' copending U.S. application Ser.No. 11/408,268, incorporated herein by reference. Preferably, the MainTask and Subordinate Task(s) that would be developed for the ApplicationLayer would carry out the system and subsystem functionalities generallydescribed in the State Control Processes of FIG. 6G1A through 6G3B, andState Transition Diagrams of FIGS. 10F1 through 10F3 9F1 through 9F3. Inan illustrative embodiment, the Main Task would carry out the basicobject motion and velocity detection operations supported within the 3Dimaging volume by each of the coplanar illumination and imagingsubsystems, and Subordinate Task would be called to carry out the barcode reading operations the information processing channels of thosestations that are configured in their Bar Code Reading State (Mode) ofoperation. Details of task development will readily occur to thoseskilled in the art having the benefit of the present inventiondisclosure.

Modifications that Come to Mind

While image-based, LIDAR-based, and SONAR-based motion and velocitydetection techniques have been disclosed for use in implementing theobject motion/velocity detection subsystem of each illumination andimaging station of the present invention, it is understood thatalternative methods of measurement can be used to implement suchfunctions within the system.

Also, all digital image capturing and processing system of the presentinvention, disclosed herein, provide full support for (i) dynamicallyand adaptively controlling system control parameters in the digitalimage capture and processing system, as disclosed and taught inApplicants' PCT Application Serial No. PCT/US2007/009763, as well as(ii) permitting modification and/or extension of system features andfunction, as disclosed and taught in PCT Application No. WO 2007/075519,supra.

Several modifications to the illustrative embodiments have beendescribed above. It is understood, however, that various othermodifications to the illustrative embodiment of the present inventionwill readily occur to persons with ordinary skill in the art. All suchmodifications and variations are deemed to be within the scope andspirit of the present invention as defined by the accompanying Claims toInvention.

1. A laser beam generation system having a integrated coherencereduction mechanism, comprising: a flexible circuit having a first endportion and a second end portion; a laser diode mounted on said firstend portion of said flexible circuit, for producing a laser beam havinga central characteristic wavelength; diode current drive circuitry forproducing a diode drive current to drive said laser diode and producesaid laser beam; and high frequency modulation (HFM) circuitry, mountedon said first end portion of said flexible circuit, for modulating saiddiode drive current at a sufficiently high frequency to cause said laserdiode to generate spectral side-band components about said centralcharacteristic wavelength, and thereby reducing the coherence as well ascoherence length of said laser beam.
 2. The laser beam generation systemof claim 1, wherein said diode current drive circuitry is mounted onsaid flexible circuit.
 3. The laser beam generation system of claim 1,wherein said diode current drive circuitry is mounted on a printedcircuit board that is interfaced with said second end portion of saidflexible circuit.
 4. The laser beam generation system of claim 1,wherein said diode current drive circuitry is mounted on said second endportion of said flexible circuit.
 5. The laser beam generation system ofclaim 1, wherein said laser diode is a diode selected from the groupconsisting of a visible laser diode and an IR laser diode (IR-LD)
 6. Thelaser beam generation system of claim 1, in combination with an opticalbeam multiplexing (OMUX) module for receiving said laser beam as inputbeam, a generating as output, a plurality of laser beam components thatare recombined to produce a composite laser beam having substantiallyreduced coherence for use in illumination applications where asubstantial reduction in speckle pattern noise is achieved.
 7. The laserbeam generation system of claim 6, wherein said OMUX module comprises: asingle glass plate bearing having an input surface and an outputsurface, and reflective and semi-reflective coatings provides on saidinput and output surfaces, so as to optically multiplex an input laserbeam entering said input surface, into multiple spatial-coherencereduced output laser beams exiting from said output surface.
 8. Thelaser beam generation system of claim 7, wherein said multiplespatial-coherence reduced output laser beams are planarized into acomposite substantially planar laser illumination beam (PLIB) by amulti-cylinder planarizing-type illumination lens array disposed inclose proximity said output surface.
 9. The laser beam generation systemof claim 7, wherein said OMUX module comprises: a glass plate bearingmirror and semi-transparent reflective coatings, and deployable in alaser-despeckling PLIM so as to reduce (i) the coherence of theresulting planar/narrow-area illumination beam generated therefrom, and(ii) thus the amount of speckle pattern noise observed at said imagedetection array of an image formation and detection subsystem.
 10. Thelaser beam generation system of claim 7, in combination with said OMUXmodule, and also a digital image detection array for detecting digitalimages of an object illuminated by said composite substantially planarlaser illumination beam; wherein the power of speckle pattern noiseobserved in a digital image of an object detected at said digital imagedetection array is substantially reduced when said digital image isformed using said substantially planar laser illumination beam.